Performace

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gett ing to grips withairc raft p erfo rm anc e

monitoring

Flight O perations Support and Line Assistance



getting to grips w

Flight Operations Support & Line Assistan

Customer Serv1, rond-point Maurice Bellonte

31707 BLAGNAC Cedex FR

Telephone (+33) 5 61 93

Telefax (+33) 5 61 93 Telex AIRBU 53

SITA T



FOREWORD

The purpose of this brochure is to provide airline flight operecommendations on the way to regularly monitor their aircraft p

This brochure was designed to provide guidelines for airmonitoring based on the feedback obtained from many opeknowledge of Airbus aircraft and systems.

Should there be any discrepancy between the information giveand that published in the applicable AFM, FCOM, AMM or SB, th

Airbus would be eager to work with some airlines on an ongoingprojected performance monitoring system well in advance of its the A380 program.

Airbus encourages to submit any suggestions or remarks conceto:

AIRBUS



TABLE OF CONTENTS

A. Introduction

B. Background

1. WHAT IS PERFORMANCE MONITORING?

2. AIM OF THE AIRCRAFT PERFORMANCE MONITORING

3. THE CRUISE PERFORMANCE ANALYSIS METHODS3.1. THE FUEL USED METHOD

3.2. THE FUEL BURN OFF METHOD

3.3. THE SPECIFIC RANGE METHOD

3.3.1. INTRODUCTION

3.3.2. DEFINITION

3.3.3. PRINCIPLE OF THE METHOD

3.3.4. HOW TO GET SPECIFIC R ANGE

3.4. CORRECTIONS AND PRECAUTIONS

3.4.1. OPERATIONAL FACTORS

3.4.2. ENVIRONMENTAL FACTORS

3.4.3. TECHNICAL FACTORS

3.4.4. T AKING INTO ACCOUNT INFLUENCE FACTORS

3.5. CONCLUSION

3.5.1. TRENDS AND FACTORING

3.5.2. COMPARING PERFORMANCE MONITORING METHODS

3.5.3. AIRCRAFT PERFORMANCE MONITORING COMMUNITY

C. How to record in-flight parameters

1. INTRODUCTION

2. REQUIRED OBSERVED DATA

3. MANUAL RECORDING3.1. MEASUREMENT PROCEDURES AND PRECAUTIONS

3.1.1. AT DISPATCH

3.1.2. PRIOR TO TAKE OFF



T ABLE OF C ONTENTS

4.4. THE CRUISE PERFORMANCE REPORT

4.4.1. GENERAL4.4.2. TWO REPORT FORMATS

4.4.3. THE TRIGGER LOGIC

4.5. DATA ANALYSIS PROCEDURE

D. Cruise performance analysis

1. THE BOOK LEVEL

2. A TOOL FOR ROUTINE ANALYSIS : THE APM PROGRAM2.1. INTRODUCTION

2.2. BASICS

2.3. THE INPUT DATA

2.4. APM OUTPUT DATA

2.5. THE APM STATISTICAL ANALYSIS

2.5.1. GENERAL

1.1.2. MEAN VALUE (µ)

1.1.3. STANDARD DEVIATION (Σ)

1.1.4. DEGREES OF FREEDOM

1.1.5. V ARIANCE

1.1.6. NORMAL OR GAUSSIAN DISTRIBUTION

1.1.7. CONFIDENCE INTERVAL

1.6. THE APM ARCHIVING SYSTEM

1.7. SOME NICE-TO-KNOWS

1.7.1. INFLUENCING FACTORS

1.7.2. AIRCRAFT BLEED CONFIGURATION1.7.3. AIRCRAFT MODEL SPECIFICS

1.7.4. PROCESSING RULE

3. HOW TO GET THE IFP & APM PROGRAMS

E. Results appraisal

1. INTRODUCTION

2. INTERPRETING THE APM OUTPUT DATA2.1. DFFA INTERPRETATION

2.2. DFFB INTERPRETATION

2.3. DSR INTERPRETATION



2.2. FMS PERF DATA BASE (PDB)

2.3. UPDATE OF THE PDB2.4. PERF FACTOR DEFINITION

2.4.1. GENERAL

2.4.2. B ASIC FMS PERF FACTOR2.4.3. MONITORED FUEL FACTOR

2.4.4. FMS PERF FACTOR

2.5. BASIC FMS PERF FACTOR2.5.1. GENERAL ASSUMPTIONS

2.5.2. A300-600/A310 AIRCRAFT

2.5.3. A320 “CFM” ENGINES2.5.4. A320 “IAE” FAMILY :2.5.5. A330 AIRCRAFT

2.5.6. A340 AIRCRAFT

2.6. PROCEDURE TO CHANGE THE PERF FACTOR2.6.1. A300-600/A310 AIRCRAFT

2.6.2. A320 F AMILY AIRCRAFT

2.6.3. A330/A340 AIRCRAFT

2.7. EFFECTS OF THE PERF FACTOR

2.7.1. ESTIMATED FUEL ON BOARD (EFOB) AND ESTIMATED LANDING

2.7.2. ECON SPEED/M ACH NUMBER

2.7.3. CHARACTERISTIC SPEEDS

2.7.4. RECOMMENDED M AXIMUM ALTITUDE (REC MAX ALT)2.7.5. OPTIMUM ALTITUDE (OPT ALT)

3. FUEL FACTOR FOR FLIGHT PLANNING SYSTEMS3.1. EFFECT OF THE FUEL FACTOR ON FLIGHT PLANNING

3.2. KEYS FOR DEFINING THE FUEL FACTOR

3.3. COMPARING FMS FUEL PREDICTIONS AND COMPUTERIZED F

4. AIRBUS TOOLS AND FUEL FACTOR4.1. THE IFP PROGRAM

4.1.1. THE IFP CALCULATION MODES

4.1.2. SIMULATION OF THE FMS PREDICTIONS

4.1.3. DETERMINATION OF THE ACTUAL AIRCRAFT PERFORMANCE

4.2. THE FLIP PROGRAM4.2.1. THE FLIP MISSIONS

4.2.2. SIMULATION OF FMS PREDICTIONS

4.2.3. DETERMINATION OF THE ACTUAL AIRCRAFT PERFORMANCE

G. Policy for updating the Fuel Factor



T ABLE OF C ONTENTS

5. WHO CHANGES THE FUEL FACTOR(S)?

H. Appendices

1. APPENDIX 1 : HIGH SPEED PERFORMANCE SOFTWARE1.1. P.E.P FOR WINDOWS

1.1.1. WHAT IS P.E.P. ?1.1.2. PERFORMANCE COMPUTATION PROGRAMS

1.1.3. THE IFP PROGRAM

1.1.4. THE APM PROGRAM1.1.5. THE FLIP PROGRAM

1.2. SCAP PROGRAMS AND UNIX VERSIONS

2. APPENDIX 2 - FUEL-USED METHOD2.1. GENERAL PRINCIPLE

2.2. MEASUREMENT PROCEDURES AND PRECAUTIONS

2.2.1. PRIOR TO TAKE-OFF

2.2.2. IN FLIGHT

2.3. DATA ANALYSIS PROCEDURE

2.3.1. NOTES

2.3.2. EXAMPLE

3. APPENDIX 3 - TRIP FUEL BURN-OFF METHOD

APPENDIX 4 - AIRBUS SERVICE INFORMATION LETTER 21-091

5. APPENDIX 5 - AMM EXTRACTS - CRUISE PERFORMANCE REPDESCRIPTION EXAMPLE

6. APPENDIX 6 - AUDITING AIRCRAFT CRUISE PERFORMANCE IREVENUE SERVICE

I. Glossary

J. Bibliography



A. INTRODUCTION

For years, the business environment has becomechallenging. Yields are dropping while competitiBusiness traffic is volatile, aircraft operations are bemore expensive and spare parts are changing Airlines are faced with new objectives to adapt to this

Fuel burn contributes up to ten percent to direct operatimaintenance is up to another quarter. The operator's main conchave a high quality information about the condition and the paircraft whenever needed.

That’s why Airbus feels deeply involved in aircraft performance mbeen proposing for years some tools for aircraft performance mo

some guidelines to perform aircraft performance audits.

Today’s aeronautics industry has been undeniably dominated acquisition of large amounts of data in all airline departments. Iflight operations have been staggering under a high flow of datathis massive data flow is to identify what is needed and for what

Amongst this huge flow of data, some may be used to monitor ta given airplane and/or of the whole fleet. Long term trend aircraft performance really takes place in the frame of maintencomplements all other monitoring methods.Likewise, aircraft performance monitoring involves the whole com- Flight crew and flight operations staff members are the

information. Indeed, data acquisition and analysis

responsibilities.- Maintenance staff members play a role in the process, as k

in the best condition possible is their main concern. Tracsurfaces, monitoring of the engine performance, calibrationnumber/altitude is their responsibility.Management offices are also involved for their awarene



I NTRODUCTION

A glossary at the end of the document gives a definition of the terms u

brochure. Finally, there is a list of documents in the bibliography that mthe interpretation of the results of the various types of analyzes.



B. BACKGROUND

The purpose of this chapter is to provide a basic knowperformance monitoring. The method used for analysis as well tools are detailed here below.

This brochure is focused on the specific range method and on th

APM program. This chapter also gives some information on ocan be used for cruise performance analysis.

1. WHAT IS PERFORMANCE MONITORING?

Aircraft performance monitoring is frame of fuel conservation and

assessment. It is a procedure devaircraft data in order to deterperformance level of each airplanerespect to the manufacturer’s book le

The aircraft performance book levelthe aircraft manufacturer and represents a fleet average of br

and engines. This level is established in advance of productionbrand new aircraft leads to individual performance above anvalue. The performance data given in the Airbus documentaOperating Manual) reflects this book value. The high-speed bstored in the high-speed performance databases used by Asoftware such as the IFP, the FLIP or the APM programs.

The performance levels are measured in their variations ov

trends can be made available to the operators’ various deperform corrective actions to keep a satisfactory aircraft conditio

The actual aircraft performance deterioration endows two maperformance degradation (fuel consumption increase for a airframe deterioration (seals doors slats and flaps rigging spoi



B ACKGROUND

2. AIM OF THE AIRCRAFT PERFORMANCE MONITORING

Results of aircraft performance monitoring are used to reach theobjectives:- To adjust the performance factor for:

the computerized flight plan, the FMS predictions and

- To monitor the aircraft condition periodically in order to analyze thegiven tail number or of a whole fleet,

- To identify the possible degraded aircraft within the fleet and take cnecessary corrective actions: Maintenance actions Route restrictions

- To demonstrate the performance factor for ETOPS which may be usof the 5% factor imposed by regulations.

It also allows operators to perform various statistics about fuel consumptsuch is a good aid to define the operators’ fuel policy.

As a general rule, regulation requires to take into account “realistic” a

consumption.

3. THE CRUISE PERFORMANCE ANALYSIS METHODS

There are mainly three methods to compare actual aircraft performancthe book value:

1. The fuel used method,

2. The fuel on board method,

3. The specific range method.

This chapter is focused on the specific range method For further details



3.1. The fuel used method

The basis of the fuel used method is to measure aircraft fuel band over a significantly long time leg and to compare it to the fuFlight Crew Operating Manual (FCOM, Flight Planning sectioSpeed Performance calculation program developed by Airbus (th

This method probably provides less information than the specificis also less constraining in terms of stability and data acquis

The method is also less accurate because of the lack of stabobserved data.

3.2. The fuel burn off method

The trip fuel burn analysis compares genuine aircraft performancflight with the forecasted computerized flight planning. Actual ai

should be corrected depending on the differences between the and the predicted one.

3.3. The specific range method

3.3.1. Introduction

The data observed in flight represents punctual (instantaneouperformance capability. It is used to generate a measured Sperepresents the actual aircraft fuel mileage capability (NM/kg ospecific range represents the aircraft/engine performance leveconditions and thus constitutes the main reference criteriorepresentative of the actual fuel consumption of the aircraft durin

3.3.2. Definition

The specific range (SR) is the distance covered per fuel burn uBasically, the specific range is equal to:

(GS)speedgroundSR =



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Moreover, SR depends on aerodynamic characteristics (Mach number

drag ratio), engine performance (Specific Fuel Consumption)1

, aircraft wand sound velocity at sea level (a0).

Figure B0 - Illustration of the contributors on the Specific Range

Where SR is the Specific Range in NM/kga0 is the celerity of sound at sea level in m/sM is the Mach Number L/D is the lift-to-drag ratioSFC is the Specific Fuel Consumption

M is the aircraft mass in kgT is the static air temperature in degrees KelvinT0 is the static air temperature in degrees Kelvin at sea leve

M . L/D SR

m SR

SFC SR

3.3.3. Principle of the method

o

0T

SR =

a M

SFCmg

TEngine

Aerodynamics

Weight

LD



The predicted specific range can be obtained thanks to Airbus fe

- The In-Flight Performance calculation program (IFP) or - The Aircraft Performance Monitoring program. This pr

compares recorded data with the performance book level.

This predicted specific range corresponds to the book level. Itthe FCOM performance charts.

The specific range method is the only technique, which enab

respective contribution of the airframe and the engines in thspecific range, even though utmost precautions must be taken w

3.3.4. How to obtain Specific Range

In the FCOM, cruise tables are established for several Mach nu

ISA conditions with normal air conditioning and anti-icing performance levels are presented in Figure B1 on next page.



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IN FLIGHT PERFORMANCE

CRUISE

3.05.15 P 9

REV 31SEQ 110

CRUISE - M.78

MAX. CRUISE THRUST LIMITS ISA N1 (%) MACNORMAL AIR CONDITIONING CG=33.0% KG/H/ENG IAS (KTANTI-ICING OFF NM/1000KG TAS (KT

WEIGHTFL290 FL310 FL330 FL350 FL370 FL390

(1000KG)

5084.0 .780 84.0 .780 84.0 .780 84.1 .780 84.7 .780 85.9 .78

1276 302 1189 289 1112 277 1044 264 992 252 955 24180.9 462 192.5 458 204.0 454 215.4 450 225.6 447 234.1 44

5284.2 .780 84.2 .780 84.3 .780 84.5 .780 85.1 .780 86.3 .78

1288 302 1202 289 1127 277 1060 264 1011 252 977 24179.2 462 190.3 458 201.4 454 212.0 450 221.3 447 229.0 44

5484.4 .780 84.5 .780 84.6 .780 84.8 .780 85.5 .780 86.9 .78

1300 302 1216 289 1142 277 1079 264 1031 252 1003 24177.5 462 188.1 458 198.6 454 208.4 450 217.0 447 223.1 44

5684.7 .780 84.8 .780 84.9 .780 85.2 .780 85.9 .780 87.6 .78

1314 302 1231 289 1159 277 1097 264 1052 252 1036 24175.7 462 185.9 458 195.7 454 204.8 450 212.6 447 216.0 44

58 84.9 .780 85.1 .780 85.2 .780 85.6 .780 86.4 .780 88.3 .781328 302 1246 289 1176 277 1117 264 1075 252 1070 24

173.9 462 183.6 458 192.8 454 201.3 450 208.1 447 209.0 44

6085.2 .780 85.3 .780 85.6 .780 85.9 .780 86.9 .780 89.2 .78

1342 302 1262 289 1195 277 1137 264 1102 252 1110 24172.0 462 181.3 458 189.8 454 197.6 450 203.0 447 201.5 44

6285.5 .780 85.6 .780 85.9 .780 86.3 .780 87.6 .780 90.1 .78

1357 302 1279 289 1214 277 1158 264 1135 252 1153 24170.1 462 178.8 458 186.8 454 194.1 450 197.1 447 194.0 44

6485.7 .780 85.9 .780 86.2 .780 86.7 .780 88.2 .780

1373 302 1297 289 1234 277 1182 264 1170 252168.2 462 176.4 458 183.8 454 190.2 450 191.2 447

6686.0 .780 86.2 .780 86.6 .780 87.2 .780 89.0 .780

1389 302 1316 289 1254 277 1209 264 1209 252166.2 462 173.9 458 180.9 454 186.0 450 185.0 447

6886.2 .780 86.5 .780 86.9 .780 87.8 .780 89.8 .780

1406 302 1335 289 1275 277 1242 264 1252 252164.2 462 171.4 458 177.9 454 181.0 450 178.7 447

7086.5 .780 86.8 .780 87.3 .780 88.4 .780 90.8 .780

1424 302 1355 289 1299 277 1277 264 1298 252162.1 462 168.9 458 174.6 454 176.1 450 172.3 447

7286.8 .780 87.1 .780 87.7 .780 89.0 .780

1442 302 1375 289 1325 277 1314 264160.0 462 166.4 458 171.2 454 171.1 450

7487.1 .780 87.5 .780 88.2 .780 89.8 .780

1462 302 1397 289 1357 277 1356 264157.9 462 163.9 458 167.1 454 165.7 450

7687.4 .780 87.8 .780 88.8 .780 90.5 .780

1482 302 1419 289 1392 277 1400 264155.8 462 161.3 458 162.9 454 160.5 450

LOW AIR CONDITIONI NG ENGINE ANTI ICE ON TOTAL ANTI ICE ON

w

FUEL = − 0.5 %w

FUEL = + 2 %w

FUEL = + 5 %

R



3.4. Corrections and precautions

In order to establish a valid comparison between observed data book level, one should clearly identify the following items. A femay indeed lead to an apparent deterioration, which may siganalysis of the actual performance deterioration.

3.4.1. Operational factors

The intent of the following is to describe the potential factors thanormal aircraft operations and which may have an adverse efperformance analysis in terms of systematic error or random erro

3.4.1.1. Assumed gross weight deviation

The aircraft gross weight deviation may be originating from three

3.4.1.1.1. Operating Weight Empty (OEW)

Error on the Operating Empty Weight (OEW) can be causeincrease of the OEW due to the incorporation of modifications, aaccumulation. This error may amount to a few hundred of kilogyears.

Both the JAA and the FAA impose that operators regularly esaircraft weight to account for the accumulated weight due to repmodifications. For more information on requirements and mean1.605 or FAA AC 120-27C.

3.4.1.1.2. Cargo hold weight

Cargo hold weight can be biased due to unweighted cargo anlast minute changes.

3.4.1.1.3. Passenger and baggage weights



B ACKGROUND

JAR-OPS guidelines

The JAA has produced specific JAR-OPS requirements on passebaggage standard weights: JAR-OPS 1.620. This paragraph proposes tpurpose of calculating the weight of an aircraft, the total weights of patheir hand baggage and checked-in baggage entered on the load shecomputed using either:

- Actual weighing just prior to boarding (if the flight

identified as carrying excessive weights) or

- Standard weight values. Male/female passengerweights can be used alternatively to all-adult standarRefer to tables below.

Type of flight Male Female Children(2~12 years old) A All flights except holidaycharters

88 kg195 lb

70 kg155 lb

35 kg77 lb

Holiday charters 83 kg183 lb

69 kg152 lb

35 kg77 lb

Table B1 - JAR-OPS Standard passenger weights including hand baggage

Note : Infants below 2 years of age would not be counted if carried by adults oseats, and would be regarded as children when occupying separate passen

Type of flight Baggage standardmass

Domestic 11 kg24 lb

Within the European region 13 kg29 lb

Intercontinental 15 kg33 lb

All other 13 kg29 lb



scheduled flights. For non-scheduled flights (76 kg) a 50 / 50

Any variation from these ratios on specific routes or flights substantiated by a survey-weighing plan.

The use of other standard weights is also considered in the JAR

- A suitable statistical method is given in Appendix 1 to JARverification or updating of standard weight values for passeng

should an airline choose to prove other weights by loooperations. This would involve taking random samples, the should be representative of passenger volume (weighing atype of operation and frequency of flights on various rvariations in passenger and baggage weights must clearly Anyway, a review of these weights would have to be peryears, and the load sheet should always contain reference

method hereby adopted.

- Results of the airline weighing survey should then be validaby the Authority before the airline-standard weight aapplicable.

FAR guidelines

The FAA has issued an Advisory Circular (ref. AC 120-27C) toand procedures for developing weight and balance control. Simit also involves initial and periodic re-weighting of aircraft (edetermine average empty and actual operating weight and CG group of the same model and configuration. The following weights were adopted and are reminded in the following tables.

Type of flight Male Female Child(2~12 yea

Summer flights(from May, 1st till October, 31st)

88 kg195 lb

70 kg155 lb

36 80

Wi fli h 91 k 3 k 36



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Type of flight Baggage standardmass

Domestic 11 kg25 lb

International and non-scheduled 14 kg30 lb

Table B4 - AC 120-27C Standard check baggage weights

When passengers belong to a very specific group such as athletic squateams… the actual weight of the group should be retained.

Similarly to JAA and FAA requests, airlines have to adopt standard weigthey request different values, which would have to be proven by a weighat the risk of ending up with higher statistics. Regional exceptions allowed when substantiated by means of an accepted methodology.

3.4.1.1.4. Impact on monitored aircraft performance

The impact of these regulatory stipulations on cruise mileage is eunderestimation of the aircraft gross weight is considered to result in anincrease of fuel used and in a decrease of specific range. It causesairframe degradation. A bias on the analysis result is often observed.

3.4.1.2. Airframe maintenance and aerodynamic deterioration

One of the penalties in terms of fuel mileage is an increased drag due tairframe condition of the aircraft. Normal aerodynamic deterioration of over a given period of time can include incomplete retraction of movingor surface deterioration due to bird strikes or damages repairs. Each deinduces increased drag and as a consequence increased fuel consumpt

The induced fuel burn penalty largely depends on the location of the draitem. These items can be classified in several groups, depending on the



If the APM program is not used but another method, it

implementing an aerodynamic inspection for example at thecheck.

In order to complement cruise performance analyses, and whenaircraft should be observed on ground (to be confirmed with phflight for any surface misalignment or other aerodynamic discrep- door misrigging (see figure B3)- missing or damaged door seal sections

- control surface misrigging (see figure B2)- missing or damaged seal sections on movable surfaces- skin dents and surface roughness- skin joint filling compound missing or damaged.

Figure B2 - Example of misrigged slat



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Figure B4 - Paint Peeli

In flight this would specifically pertain to :

- slats alignment and seating- pylons and pylon – to – wing interfaces- engine cowlings- spoilers trailing edge seating and seal condition (rubber or brush)- flaps, flap tabs and all-speed ailerons trailing edge alignment.

On ground this would specifically pertain to most forward and middle are- Static and dynamic pitot condition

- Nose radome misalignment- Cargo door to fuselage alignment- Service door condition- Engine fan blade condition (curling,

etc).- Surface cleanliness (hydraulic fluid,

dirt, paint peeling (see figure B4),

etc).- Under-wing condition- Wing-body fairing- Nose and main landing gear door

adjustment- Temporary surface protection remnants.

Figure B5 shows an example of a very unclean aircraft. This para

assessment shows an estimated amount of 6.09 extra drag count res2%-loss of Specific Range.

More details on that subject is available in another Airbus publicatiohands on experience with Aerodynamic deterioration” (see Chapter J-Bibdocument [J-3] ).



GENERIC EXAMPLE



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3.4.1.3. Aircraft trimming and asymmetry diagnosis (BIAS)

Accurate and repetitive trimming allows to identify the origin of small butasymmetries to be identified especially on A300B2/B4 and A310 / aircraft.

The reasons for these asymmetries can be several:

- General production tolerances, particularly wing tolerances and between both wings in dimensions, wing / fuselage local setting, wing

- Control surface rigging tolerances, particularly for rudder, ailerons an- Fuel loading asymmetries between both wings, although displayed F

are symmetrical- Thrust setting asymmetries between both engines, although displ

EPR values are symmetrical- Cargo or passenger loading asymmetries.

All of these could lead to an aircraft not flying straight in cruise with adirectional control surfaces in perfectly neutral positions.

On A310/A300-600 aircraft, Airbus recommends to laterally trim an asyaircraft with the zero control wheel technique because it is less fuel cthan any other technique.

On fly-by-wire aircraft, the flight control system compensates almostchanges of trim due to changes in speed and configuration. Changeresult in higher changes in trim and are compensated for by changing tattitude.

The apparent drag, resulting from a lateral asymmetry of the aircrafcruise performance analysis. On A310/A300-600, an aircraft lateral acan result in a 0.3% deterioration of the specific range.

Procedures for checking the aircraft lateral symmetry are given in the FOperating Manual:- In section 2.02.09 for A310 and A300-600 aircraft types



conditions can be calculated from the IFP and can be co

measured difference in fuel consumption / SR with and without cases where this measured difference is below the nominal difhypothesized that some bleed leaks in the anti-ice ducts may engine fuel flow deviation with anti-ice off. This test is performpurposes only, and suggests the possibility of leaks without necthe extent or amount of actual engine deviation.

For the purpose of performance monitoring, Airbus recommend

as stabilized conditions as possible. In particular, the bleed cobe as follows to have the data collected:- anti ice OFF- air conditioning NORM Additionally, asymmetrical bleed configuration must be avoidedata for analysis. In case of asymmetrical bleed configurautomatically recorded via the Data Management Unit (DMU) or Interface and Management Unit (FDIMU).

3.4.2. Environmental factors

Weather is one natural phenomenon that man has not yet learntalthough accuracy is really increasing. Weather has of a craircraft performance and on the outcome of the flight operations.

The intent of the following is to describe potential factors often

may have a significant effect on cruise performance analysis in t

3.4.2.1. Isobaric slope due to pressure gradient

The International Standard Atmosphere (ISA) model assumesdecreases with altitude. This model is a very reliable law, enatemperature, pressure, density of the atmosphere, depending on

The surfacpressure horizontal.

Surfaces of constant ressure



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Of course, the principle shown in figure B8 is theory. When an aircraft

long ranges, the weather conditions change continuously. In particular, geometric height, pressure varies. Or the other way around, for apressure, the geometric height will for sure vary.

Therefore, when flying along an isobaric line,

• In LP zones, the aircraft actually descends relative to lifting air imaintain pressure altitude. Hence aircraft performance is slightly breality (since Mach number slightly increases).

• In HP zones, the aircraft actually climbs relative to lifting air in order tthe pressure altitude. Thus, the aircraft performance is slightly wreality (since Mach number slightly decreases).

The aircraft vertical velocity can be estimated from the wind and pressurmaps at a given FL and on a given sector. On this type of maps (see FIsobaric or iso-altitude lines are indicated. As a reminder, 1 hPa near the

equivalent to 28 feet while 1 hPa at FL380 is equivalent to 100 feet.



Weather offices can provide isobars at different altitudes, indicat

(FL): FL50/850 hPa, FL100/700 hPa, FL180/500 hPa, FL250/30hPa, FL390/200 hPa.

Thus, as a result of the isobaric surface slope, the aircraft maydownhill depending on the pressure field. In performance demonisobars are usually followed to minimize drift angle. In airline revis not feasible since airways cut across the isobars.

The isobaric slope can be related to the drift angle as illustrated



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The opposite phenomenon prevail in the Southern Hemisphere.

Wind velocity increases below the tropopause and decreases atropopause by approximately 5% per 1000 ft except in jet stream zonestropopause, the wind velocity is maximum.

In order account for the isobaric slope, the aircraft should be given a boflying uphill (LH drift angle in Northern Hemisphere, RH drift angle inhemisphere) and a penalty when the aircraft is flying downhill (RH dr

Northern hemisphere, LH drift angle in Southern hemisphere).

The correction is applied on theSR

∆SR (or

FU

∆FU − ) as follows:

tan(DAsin(LAT)TAS101.107SR

SR ∆ 2

CORR CORR

××××−=

∆−=

−

FU

FU

where TAS is the true airspeed in knotsDA is the drift angleLAT is the latitude



In practice, drift (track-heading), temperature (SAT) and w(direction/speed) allow to consider: Pressure patterns (high and lows) Wind barbs (direction/speed / FL) Tropopause height Stratospheric lapse rate Temperature trends around tropopause Jetstream core locations

Turbulence

In any case the aircraft must be stabilized (Flight Path AccVelocity).

Whilst carrying out an aircraft performance monitoring audit, from taking stabilized cruise performance readings if the prchanging rapidly or when drift angles are greater or equal to 5 de

a positive ∆T can be observed (≅ 10° C in horizontal flight) whethe tropopause from the troposphere to the stratosphere. increase is even more noticeable when the tropopause slope atherefore when wind velocity is highest at the point where passed through.

The equation in Figure B11 is valid only for high-altitude wind

conditions like topographic effects (mountain waves) or strongisobars > 5° drift would lead to erroneous results.

3.4.2.2. Isobaric slope due to the temperature gradien

The International Standard Atmosphere (ISA) model assumes pwith altitude. This model is a very reliable law, enabling to reprepressure, and density of the atmosphere, depending on the altitu

From the ground up to the tropopause, the mean tempecontinuously with altitude (see figure B12 on next page).



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Figure B12 - ISA Temperature model

Indeed, in the real world, at a given FL, the temperature changes conEngine efficiency depends on the difference between the fuel temperattanks, the temperature is fixed) and the outside air temperatutemperature, SAT). In cruise, if the SAT increases, engine thrust decrvice-versa. The autothrust corrects this in order to maintain the pressureRecordings should be performed in a zone where the SAT is forecasted

-2°C/1000ft

FeetMeters

Tropopause11 000 m 36 000 ft

7 500 ft

2 300 m

+15 °C-56.5 °C

40

40 40

41

39

Recording



In order to verify the influence of the temperature gradient on airthe following should be considered. Temperature gradients alsoof the isobaric surfaces. For example, low-pressure areas are high-pressure areas but the colder the low pressure, the stesurface slope.

Figure B14 - Illustration of the isobaric slope due to the temperat

In order to compensate for the modified isobaric slope, the aircbonus or a penalty depending on the temperature gradient, and

( ) SAT11.5FL0.25104.9SR

SR ∆ 3

CORR ∂××−×××=

−

D

L

C

C

A graphic example is given in following Figure B15.

15 °C0 °C

140 ft 132 ft



B ACKGROUND

Note: The usefulness of these isobaric slope corrections is, in fact, rather questithe theoretical assumptions are usually not applicable to the real atmosphe

are looking for is the change in potential energy represented:

by the slope of the flight path, and / or

by the change of geopotential altitude

However, when performing an assessment of this slope through the ob

and/or temperature trend, only the conditions between, earth’s surface and are relevant ; this applies for both the assessment of the pressure-related sas for a temperature related slope. There is presently no system which isensing flight path slope with the required accuracy (better than 0.002°).

The only valuable approach today is to compute this slope from inertial inforthen would include all possible isobaric slope effects (pressure or geostrophic winds) without having to distinguish between those.

3.4.2.3. Winds and Pressure zones

Let us start with basic reminders on winds and pressure zones.

3.4.2.3.1. Wind

At high altitudes, the wind direction follows isobaric lines, while at low altwind direction cuts through isobaric lines.

As illustrated on figure B15bis, when crossing over isobaric lines, and wNorth hemisphere (the contrary for South hemisphere)



Figure B15 bis - Wind / Pressure zones relationship

3.4.2.3.2. Pressure versus wind relationship

Pressure variations are linked to the wind velocity. Indeed, Low wind velocity corresponds to slow pressure variations High wind velocity corresponds to quick pressure variations

Thus, at a given flight level or pressure altitude, successive distant with weak wind, close with strong wind.

As a result, the wind force is linked to the pressure distribuconsequence, it has an impact on the actual aircraft profile.

3.4.2.4. Low and high pressure zones

The low pressure (LP) zones are small and scattered. The concentrated and close to circles. In these LP zones, the air is ustrongly. Some turbulence may be encountered.

The high pressure (HP) zones are wide. Isobaric lines are awkward shapes. In these HP zones, the air is stable and gently

L H



B ACKGROUND

Figure B16 - Example of HP and LP zones

In practice, the air mass vertical velocity cannot be measured on board tThe aircraft trim is modified to maintain pressure altitude.

In Europe, statistical air vertical velocities encountered are centime0.01m/s to 0.1 m/s). Worldwide, the mean value of vertical winds enco0.6 m/second.

Most of the monitoring procedures probably do induce a unfavorable bia

performance measurements because the crew usually concentratesatmospheres. As explained above, extremely calm atmospheres ncorrespond to sinking zones since these tend to increase stability. The therefore to estimate the bias that can be attributed to vertical winpreliminary study, the specific range deviation generated by an air ma

L

H



3.4.2.5. The Coriolis effect

The Coriolis effect is the tendency for any moving body on or surface to drift sideways from its course because of the earth's (west to east) and speed, which is greater for a surface pointthan towards the poles.

In the Northern Hemisphere the drift is to the right of the bodSouthern Hemisphere, it is to the left.

The Coriolis deflection is therefore related to the motion of the of the Earth, and the latitude. The Coriolis acceleration resultsdecrease of the apparent aircraft gross weight.

cos(LAT)sin(TT)GS107.63GW

GW 6 ××××−=∆ −

Where GW is the aircraft gross weightGS is the ground speed in knotsTT is the true trackLAT is the latitude

At a given ground speed and latitude, In the Northern Hemisphere, the aircraft gross weight incr

westwards and decreases when flying eastwards. In the Southern Hemisphere, the aircraft gross weight decr

westwards and increases when flying eastwards.

In order to account for the gross weight deviation, a positive co

aircraft is flying westwards and negative correction when theastwards (in Northern Hemisphere, and vice versa in the Soutcould be applied to the specific range.

The correction is applied on theSR

∆SR as follows:

BACKGROUND



B ACKGROUND

Hence,

cos(LAT)sin(TT)GS107.63SR

SR ∆ 6

CORR

×××××−=

−k

Where GS is the ground speed in knotsTT is the true trackLAT is the latitude

3.4.3. Technical factors

3.4.3.1. Fuel Lower Heating Value (Fuel LHV)

The Fuel LHV defines the fuel specific heat or heat capacity of the fuel. unit for this parameter is BTU/LB.

Fuel flow is directly impacted by this value. The effect of the fuel LHapparent cruise performance level is explained below thanks to a basicof the operation of a gas-turbine engine.

The engines are required to produce a certain amount of thrust (i.e. thrust setting parameter is required) to maintain the aircraft in steady cflight. For given flight conditions, a given engine provides an amountwhich depends on the amount of heat energy coming from the fuel burcombustion chamber.

The heat energy per unit of time is given by the following formula:

Q = J x Hf x Wf

Where J is physical constantHf is the fuel specific heat (Fuel LHV) in BTU1/lbWf is the fuel flow in lb/h

As a consequence, the fuel flow required to produce a given amount of t



The following conclusions can be drawn from the above equation

1. Any deviation in the fuel LHV will result in a deviation in fuel f

2. As the heat energy remains constant whenever fuel LHV andengine thermodynamic cycle is unchanged. The high-pressuand the Exhaust Gas Temperature remain unchanged.

3. The only affected parameters are fuel flow (FF) and specific

FLHV

FLHV

FF

FF ∆−=∆ and

FLHV

FLHV

SR

SR ∆+=∆

The FLHV local and seasonal variations being a fact of industry

be increased by a FLHV measurement.

It is in any case essential to perform FLHV measurements, asquality exist throughout the world (crude oil quality) and in betwnow has a fairly large database we have been receiving lots ofaudits worldwide as shown in figure B17.

BACKGROUND



B ACKGROUND

Figure B17 - FLHV values versus fuel density - Sample measurements

Figure B17 shows that the minimum fuel LHV encountered over a population of samples is 18400 BTU/LB.In routine performance analysis, this FLHV is rather difficult to obtain, bthe wide variety of fuel quality, depending on various world regions. Mairlines subsequently use the same value for all their analysis. Althmethod is rather questionable if an accurate performance audit is intequite acceptable for routine analysis.

In this case, one should keep in mind the FLHV effect on the monitored especially when implementing the fuel factors in the airline flight planningor in aircraft FMS systems. The monitored fuel should be corrected foreffect (see also chapter 0 -2.4.3. Monitored fuel factor & 0 -3.2.Keys for dfuel factor ).

FLHV BTU/LB)



Figure B18: Stable frame = PMAX-PMIN < DP limit for all para

The FDIMU/DMU collects most of the data. The data comesaircraft systems (such as the ADIRS, the FAC…). Potential aremains in the normal industrial tolerances for each of these sys

Some of the data is measured by the systems, and thereformeasurement error. Some other data (such as the flight parameter, which quantifies the change of aircraft speed along calculated by means of the FDIMU/DMU based on an averagparameters. As a consequence, a rounding error comes

measurement and tolerance errors.

Yet, the total error on the overall data collection remains quite loto the other potential sources of errors described in this chapter.

O th d t t i i id ( ith i ACARS d i

B ACKGROUND



3.4.4. Taking into account influence factors

When doing an aircraft performance audit, it is important to deal with all / scatter effects in the best way possible. The following meconsiderations/corrections factors are essential:

Introducing bias Introducing scatte

Fuel LHV data acquisition/transmission

Aircraft weight instrument scatter

air conditioning / bleed selectionoptions

Auto-throttle / autopilot activity

aircraft trimming atmospheric influences

instrument accuracy stabilizer / elevator / trim

When doing routine aircraft performance monitoring, it is difficult to try the impact of the previously mentioned factors. Indeed, taking a fuel samlaboratory for each flight is really not feasible. Hence, some assumptionmade, leading to introduce some uncertainty on the cruise performance

Routine aircraft performance monitoring is based on a statistical approagives an average deterioration and the associated scatter.



* A I R B U S C R U I S E P E R F O R M A N C E * A I R C R A F T P E R F O R M A N C E M

* ==================================================================================================

* *** PROGRAM: A P M - Version 2.43 - Jul. 2002 ***

*

* ------ AIRCRAFT TYPE: A319-114 ENGINE TYPE: CFM56-5A5 ----------

*

* ------ DATABASES: AERODYN. : A319113.BDC DATE:

* ---------- ENGINE : M565A5.BDC DATE:

* GENERAL : G319113.BDC DATE:

*

* ------ JOB-INFORMATION: ----------

*****************************************************************************************************

DIRECT ANALYSIS OUTPUT (INPUT BY ADIF)

DATA BLOCK/FLEET: 1/ 1

F L I G H T D A T A

CASE IDENTIFICATION

ALT MACH TAT WEIGHT CG

NO. TAIL-NO DATE FL-NO CASE ESN1 ESN2 ------------------------------------------

D/M/Y (UTC) FEET - C LB %

1 AIB001 25/05/02 202 22:55 733266 733267 37011. 0.8015 -32.55 119400. 23.7 2 AIB001 24/05/02 471 11:59 733266 733267 39003. 0.7700 -38.30 122300. 25.2 -

3 AIB001 07/06/02 850 11:54 733266 733267 37017. 0.7990 -21.85 123500. 25.7

4 AIB001 29/05/02 1019 13:27 733266 733267 39006. 0.8000 -35.75 119000. 24.2

5 AIB001 04/06/02 1019 18:16 733266 733267 38988. 0.7765 -21.95 122250. 24.9

6 AIB001 28/05/02 1020 21:38 733266 733267 37010. 0.7805 -34.45 128450. 24.4

7 AIB001 10/06/02 1023 23:21 733266 733267 37004. 0.8000 -19.65 130000. 23.9

8 AIB001 10/06/02 1515 11:04 733266 733267 39001. 0.7995 -27.75 114000. 24.7 -

9 AIB001 27/05/02 1550 21:38 733266 733267 37024. 0.7990 -30.95 126200. 25.7

10 AIB001 03/06/02 1550 21:48 733266 733267 37028. 0.8005 -30.05 127900. 25.1

11 AIB001 19/05/02 1628 19:51 733266 733267 37003. 0.7990 -33.85 120700. 26.3

12 AIB001 24/05/02 1835 20:05 733266 733267 35012. 0.8015 -24.75 134050. 24.1

* A I R B U S C R U I S E P E R F O R M A N C E * A I R C R A F T P E R F O R M A N C E

* ==================================================================================================


*

* ------ AIRCRAFT TYPE: A319-114 ENGINE TYPE: CFM56-5A5 ----------

*

* ------ DATABASES: AERODYN. : A319113.BDC DATE:

* ---------- ENGINE : M565A5.BDC DATE:

* GENERAL : G319113.BDC DATE:

*

* ------ JOB-INFORMATION: ----------

*****************************************************************************************************

AIRCRAFT TAIL-NO.: AIB001 DIRECT ANALYSIS OUTPUT (INPUT BY ADIF) DA

E N G I N E D A T A

N11 N12 FFA1 FFA2 EGT1 EGT2 BC WBLL WBLR FLHV N1TH FFTH FFC1

NO. ------------------------------------------------------------------------------------------------

% % LB/H LB/H C C LB/S LB/S BTU/LB % LB/H LB/H

1 86.60 85.70 2410.0 2440.0 584.0 581.0 0.960 0.960 18590. 86.05 2405.5 2468.3

2 85.80 85.80 2180.0 2180.0 576.0 576.0 0.930 0.930 18590. 85.41 2139.1 2179.2

3 88.40 88.20 2500.0 2530.0 626.0 624.0 0.960 0.960 18590. 87.99 2481.7 2530.8

4 87.00 87.00 2340.0 2370.0 596.2 603.0 0.930 0.860 18590. 86.81 2306.7 2327.7

5 89.20 88.90 2420.0 2430.0 647.0 646.0 0.930 0.930 18590. 89.16 2348.2 2352.1

6 86.50 86.20 2440.0 2440.0 585.6 590.6 0.930 0.940 18590. 86.11 2394.2 2437.7

7 89.60 89.50 2630.0 2670.0 648.8 648.4 0.960 0.960 18590. 89.19 2600.1 2648.9

8 87.00 86.90 2280.0 2280.0 608.0 609.0 0.930 0.930 18590. 87.32 2264.9 2231.2

9 86.60 86.50 2460.0 2470.0 593.0 593.0 0.960 0.960 18590. 86.55 2435.2 2441.1

10 87.30 86.90 2510.0 2520.0 604.0 601.0 0.960 0.960 18590. 87.27 2507.9 2511.4

11 85.90 85.70 2390.0 2380.0 579.0 583.0 0.930 0.930 18590. 85.71 2378.0 2400.7

12 87.90 87.60 2770.0 2760.0 612.2 618.6 0.960 0.960 18590. 87.69 2730.7 2756.8

B ACKGROUND



* A I R B U S C R U I S E P E R F O R M A N C E * A I R C R A F T P E R F O R M A N C E M O N I T O R

* ===============================================================================================================


*

* ------ AIRCRAFT TYPE: A319-114 ENGINE TYPE: CFM56-5A5 -----------------------

*

* ------ DATABASES: AERODYN. : A319113.BDC DATE: 27/07/00

* ---------- ENGINE : M565A5.BDC DATE: 06/06/96

* GENERAL : G319113.BDC DATE: 26/02/01

*

* ------ JOB-INFORMATION: -----------------------

******************************************************************************************************************

AIRCRAFT TAIL-NO.: AIB001 DIRECT ANALYSIS OUTPUT (INPUT BY ADIF) DATA BLOCK/FLEE

A P M D E V I A T I O N D A T A

DN11 DN12 DFFA1 DFFA2 DFFB1 DFFB2 DEGT1 DEGT2 DN1M DFFAM DFFBM DEGTM

NO. -----------------------------------------------------------------------------------------------------------

% % % % % % % % % % % %

1 0.547 -0.353 2.612 -1.726 -2.364 3.215 0.765* 1.980 0.097 0.443 0.365 1.368 2 0.392 0.392 1.877 1.877 0.036 0.036 1.531 1.531 0.392 1.877 0.036 1.531

3 0.412 0.212 1.978 1.023 -1.217 0.914 1.414 1.535 0.312 1.500 -0.157 1.474

4 0.190 0.190 0.909 0.785 0.529 1.943 1.666 2.575 0.190 0.847 1.235 2.120

5 0.037 -0.263 0.168 -1.188 2.886 4.729* 2.174 2.573 -0.113 -0.510 3.801* 2.373

6 0.393 0.093 1.820 0.442 0.093 1.466 1.282 2.377 0.243 1.131 0.774 1.828

7 0.411 0.311 1.877 1.420 -0.713 1.252 1.678 1.805 0.361 1.649 0.267 1.742

8 -0.321* -0.421 -1.490* -1.956 2.187 2.674 2.223 2.510 -0.371* -1.723* 2.430 2.366

9 0.051 -0.049 0.241 -0.232 0.775 1.664 1.650 1.820 0.001 0.005 1.218 1.735

10 0.031 -0.369 0.142 -1.674 -0.057 2.195 1.628 1.978 -0.169 -0.766 1.059 1.803

11 0.194 -0.006 0.954 -0.032 -0.445 0.116 1.556 2.395 0.094 0.461 -0.166 1.975

12 0.207 -0.093 0.955 -0.436 0.480 1.516 1.211 2.465 0.057 0.259 0.995 1.836

MV 0.260 -0.030 1.230 -0.142 0.183 1.545 1.637 2.129 0.133 0.627 0.733 1.846

SD 0.179 0.278 0.848 1.294 1.402 0.973 0.318 0.398 0.185 0.865 0.773 0.321

NR 11 12 11 12 12 11 11 12 11 11 11 12

* VALUES OUT OF RANGE (MARKED BY A TRAILING "*") ARE NOT INCLUDED IN MEAN VALUES (MV) AND STANDARD DEVIATIONS (SD SO NUMBER OF CASES MAY BE REDUCED TO NUMBER OF READINGS (NR). ".---" MEANS FAILED OR NOT CALCULATED.

Figure B20: Trending with the APM program

Figure B20 analysis shows that this particular tail number consumes than the IFP book level by 1.228% (worse specific range by 1.228%) inBased on the sample in-flight records that were snapshot during the

deviation to this mean value was ±0.65%. Eleven records were used to

the statistics.

More details concerning data interpretation is available in ChapterPerformance Analysis.

3.5. Conclusion

3.5.1. Trends and factoring

Routine aircraft performance monitoring is double-purpose. First, it eestablish the different fuel factors for aircraft operations for each individu



To illustrate the trend of the aircraft performance deterioratiobased on the feedback from A320 family customers, the followin

performance values in terms of specific range versus the corresare as follows:- after 1 year from delivery: 2.0% below IFP +/- 1%- after 2 years from delivery: 3.5% below IFP +/- 1%- after 3 years from delivery: 4.0% below IFP +/- 1%

3.5.2. Comparing performance monitoring methodsMoreover, when checking the actual performance level of an airmay influence the analysis by introducing bias and/or scatter. Almay be calculated for each individual factor, this procedure aphard when routine performed.

Overall, three basic methods are available to check the actual

of the aircraft versus the book level: the specific range metho

used method (FU

FU∆), the fuel on board method (

FBO

FBO∆). D

method used, part or all of the influencing factors are taken imethod gives an apparent performance level of the aircrcombination of the actual aircraft performance level and of the in

Figure B21 illustrates how the specific range method, the fuel fuel on board method relate to each other and relative to the IFP

SR∆

FU

FU∆

FBO

FBO∆

STABILZATION(Flight Path and Atmosphere)

PREDICTION VARIATIONS(Flight Profile and Conditions)

1% (0.5%

2% (1% to

B ACKGROUND



All the above methods naturally have relative advantages and disawhich airlines have to weigh out against each other.

Advantages Disadvanges Comm

Specificrangemethod

Potential splitting of engine and airframeEasy processing

Scatter, sensitiveStability critical

Not adfactorshort/

Fuel-usedMethod

Easy data gatheringScatter elimination

ATS remaining in use

No bias eliminationTedious processing

Adaptplann

condiTrip fuelburn-off analysis

Scatter elimination ATS remaining in use

More crew attentionrequired Tedious datagathering andprocessing

Adaptfactorhaul.

4. AIRCRAFT PERFORMANCE MONITORING COMMUNITY

Aircraft Performance Monitoring involves many actors within the airlinnext page, a sample data flow was drawn for a typical airline. Of corganization of the airline may impose different data flows but this aiman overall idea of the task sharing when dealing with aircraft pemonitoring.



R02-5000.000³ 99SEP24³ 13:46:21³ XXXXXX³

01:06:59³ CRUISE PERFORMANCE ³

5000³ "BEST" STABILITY

³ 04034B20³ .F-GLZE³ 00000036³ 00000000³

12210.00³ XXXXXX³ XXXXX ³ 000A340³SE1N03

A340 CRUISE PERFORMANCE REPORT <02>

PAGE 01 OF 02

ACID DATE UTC FROM TO FLT

CODE CNT

C1 .XXXXXX XXXXXX 01.06.59 XXXX XXXX XXXXXXXXXX

5000 849 68

PRV PH TIEBCK DMU IDENTIFICATION MOD AP1

AP2

C2 001 06.0 000000 SXXXXX XXXXXX XXXXX 000 052

052 28

TAT ALT MN SYS (....... BLEED STATUS

.......) APU

C3 N18.5 37000 0.821 111 1.19 1111 1010 0 0101

1111 1 17 - AF

R02-5000.000³ 99SEP24³ 13:46:21³ XXXXXX³



³ 04034B20³ .F-GLZE³ 00000036³ 00000000³



PAGE 01 OF 02


CODE CNT


5000 849 68


AP2


052 28


.......) APU

C3 N18.5 37000 0.821 111 1.19 1111 1010 0 0101

1111 1 17 - AF

R02-5000.000³ 99SEP24³ 13:46:21³ XXXXXX³



³ 04034B20³ .F-GLZE³ 00000036³ 00000000³



PAGE 01 OF 02


CODE CNT


5000 849 68


AP2


052 28


.......) APU

C3 N18.5 37000 0.821 111 1.19 1111 1010 0 0101

1111 1 17 - AF

Snapshots of

cruise data

FLIGHT OPERATIONS OR

DEDICATED STAFF MEMBERS

IDENTIFYDEGRADED

AIRCRAFT

B ACKGROUND



LEFT INTENTIONALLY BLANK

H OW TO REC



C. HOW TO RECORD IN-FLIGHT PARAMETThis chapter introduces to the Airbus’ methodology for fuel milein terms of monitoring procedures and data retrieval.

1. INTRODUCTION

Data retrieval is the key point to aircraft performance monitorinthe quantity of records will govern the reliability of performancgreat extent. Two procedures for data retrieval from the aircraft w1. Manual recording of in-flight data based on data monito

performance.2. Automatic recording of in-flight data based on the use of

board the aircraft.

These procedures have been developed to monitor cruise pestable flight conditions.

For all aircraft types, data collection can be performed manuadedicated staff member in the cockpit or by one of the pilots. that the manual data collection quickly becomes tedious performance level is monitored systematically and repetitively.

That is why Airbus promotes the automatic data collection (wheroutine aircraft performance monitoring. Airbus worked this ostandard report format produced by aircraft systems and a tool able to cope with the report without any further handling operatio

Note that both procedures should give the same results and thamethod remains at the user’s discretion. Both methods are not be performed simultaneously and independently from each reliability of data readings.

H OW TO RECORD IN - FLIGHT PARAMETERS



2. REQUIRED OBSERVED DATA

The data that is required for further analysis is given below. Each obsset is like a snapshot of aircraft condition. As many records as possibleobtained so as to increase the statistical adequacy of performance analy

Parameter Unit Comments

Aircraft Tail Number (–)

Date YYMMDDFlight Number (–)

1-99 Number of data of a same flighvalue is set, the program sets a "1"

Flight Case or DMU recording time

hhmm Time at which the performance potaken in flight.

Engine serial numbers (–)

Altitude (ft) From the two air data computers (A

Mach number (–) From the two air data computers (ATotal Air Temperature (°C) From the two air data computers (A

Aircraft mass (weight) (kg or lb)

Center of Gravity (%)

Flight Path Acceleration (g) Horizontal acceleration measured i

Vertical Velocity (ft/min) Vertical acceleration

True Heading (°) Optional - used only if gravity coactivated.

Latitude (°) Optional - used only if gravity coactivated.

Wind speed (kt) Optional - used only if gravity coactivated.

Wind direction (°) Optional - used only if gravity coactivated

Average fueltemperature

(°C) NOT ACTIVE

Average fuel density (l/kg) NOT ACTIVE

N1 - Power settingEPR - Power Setting

(%)(–)

Depends on engine type EPR for and P&W engines, N1 for GE anengines.

Actual fuel flow (kg/h, lb/h) Fuel flow for each engine (FFA1, F

Exhaust gas (°C) To be set for each engine (EGT1

H OW TO REC



3. MANUAL RECORDING

Manual readings have to be performed when the aircraft is notappropriate equipment required for automated data retrieval. This detailed in the next paragraph.

Doing manual readings requires to comply with strict rules tpoints. Some highlights will also be given concerning analysis p

use of recording systems.

3.1. Measurement procedures and precautions

A performance monitoring must be carried out consideringmeasurement procedures and precautions.

These recommendations have been summarized in the form gthis paragraph.

3.1.1. At dispatch

- Take a copy of the computerized flight plan, the weather load sheet.

- Take a fuel sample from the refueling truck for analysis of the fuel LHV. The FLHV of the sample can be determinlaboratories.

- Check the external aspect of the aircraft to detect any seaflight control surface and door misrigging, any airframe rsurface condition, which all could increase the aircraft dand annotate aircraft schematics to detail observations.

- Note aircraft tail number, date and flight sector.

3.1.2. Prior to take off




3.1.3. In flight

- Check the aircraft is flying in cruise on a straight leg that will take minutes.

- Perform fuel balancing if unbalance between wing tanks exists. unbalance is not due to a fuel leak.

- Disconnect autothrust and set N1/EPR at an appropriate value to constant speed

- Do not touch the thrust levers during the whole subsequent perrecordings are stopped because of instability.

- Engage autopilot in ALT HLD/HDG SEL mode.

- Select air conditioning flow normal, both bleeds packs ON, engiOFF, wing anti-ice OFF.

- Wait for 5 minutes for aircraft stabilization before starting the data(take EGT, ground speed and SAT as references).

- Check the initial drift angle is less than 5 degrees and that tchange does not exceed 0.5 degree per minute.

- Start the recording process after stability criteria are achievedparagraph 3.1.4. Data Recording ).

Notes1. When flying on a long-range flight, it is recommended to collect data

gross weight/altitude combinations whenever possible (high gross altitude at the beginning of a flight, low gross weight/high altitude at a flight).

2. A visual inspection of spoilers, ailerons, slats and flaps positioconducted in cruise, to detect any possible aerodynamic disturba

H OW TO REC



3.1.4. Data Recording

Data recording will be carried out during at least 6 minutes if conditions are maintained.

Data recordings samples will be validated considering the criteria:

- Delta pressure altitude: ∆Zp ≤ ± 20 ft

- Delta static air temperature: ∆SAT ≤ ± 1°C

- Delta Ground Speed to delta time ratio: min/1ktt

GS ≤∆

∆

- Delta Mach Number: ∆Mach ≤ ± 0.003.

- Drift angle less than 5 degrees

The following parameters will be recorded at the rate specified in

Parameter Note atintervals of

Parameter

- Altitude (Zp)- Mach (M) / TAS- TAT / SAT- N1 (or EPR)- CG and rudder

trim

60 seconds60 seconds60 seconds60 seconds60 seconds

- Fuel flow (FF)- EGT- Fuel used (FU)- Ground speed (GS

In addition the approaching station will be noted, as well as thdrift angle is a triggering condition used to assess one record.Heading, wind velocity and direction, track will be also modetermine their respective impact due to the Coriolis effectoptional step as the Coriolis effect is of a second order effect.



4 / / / / / / / / / / /



A / C N o

F l i g h t N o

R E P O R T I N I T I A L W

E I G H T

K G

C G

%

H E

A D I N G

D E G

L A T

I T U D E

D E G

1

2

3

4

1

2

3

4

1

2

3

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

/

F F

F U / E G T

M N

A L T

Y S I S - F L I G H T O

B S E R V A T I O N F O R M

W i n d ( f o r c e a n d d

i r e c t i o n ) , b a l a n c e o f f u e l i n t h e

t a n k s

T A T

W I N D

H D G / F

N 1 / E P R

P a g e

S T A R T T I M E

S A T

D E G

D E G

D R I F T A N G L E




3.3. Data analysis procedure

Based on in-flight recorded data, aircraft stability will be assessed from tspeed. The most representative of a 6-minute run will be selected. One minute shots will be retained if possible. Stability criteria given in theparagraph will also guide this choice.

The input data must be prepared for and analysis according to the follow- Pressure altitude, Mach number, TAT, N1 (or EPR) and fuel flo

averaged over the selected 6 minute-portion.- Aircraft gross weight will be based on the difference between ramp

MES and fuel used at center point of the selected 6 minute-portion.- The aircraft CG will be calculated from takeoff CG and fuel schedule

part of the recorded data)- Aircraft acceleration along the flight path (FPAC) will be the slo

regression) of ground speed over the 3-minutes frames ; the same the vertical speed but sloped through altitude.

FLHV, latitude, heading are introduced to take into account fuel caloriand Coriolis / Centrifugal and local gravity effects respectively as dischapter B.

The selection of 6 minute-portions from the recorded data enables tomean value, to evaluate scatter, which is indicative of measurement sta

assessment is only possible when taking into account correction factorsturn, also allow to decrease bias and scatter. In particular, the applicaFPAC correction effectively reduces scatter. An uncorrected FPAC of corresponds to a drag deviation of approximately 1.3%.

Then, for each 6-minute segment, one set of data is obtained. The anaresulting points can be performed with an Airbus specific tool, basspecific range method: the APM program.

Statistical elimination can be selected before the analysis in the APM proeach parameter (fuel flow, N1/EPR,…), the mean value and the standardis calculated over all the records. The user can filter these records so asof lesser quality readings

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4. AUTOMATIC RECORDINGS

4.1. What is automatic recording?

Manual recording was introduced in paragraph 3. It is obvioucollecting data cannot apply in case of routine aircraft performan

At Airbus we have conceived a process, that minimizes handlinprocess is based on the utilization of the aircraft recording

collection. Automatic recording means configuring aircraft systeflight data automatically recorded for further analysis by the IFP

To accomplish this, some specific systems are required to grelevant format. The next paragraph will give a basic comprehenrecording systems. Note that the description depends on the airc

4.2. A300/A310/A300-600 aircraft

The aircraft data recording system includes an expanded AircraSystem. The AIDS allows condition and performance monitoriengineering investigations by the operators. An additional optional Data Management Unit (DMU) can also b A300/A310/A300-600 aircraft types, all equipment is Buyer Fur(BFE).

Airbus is not responsible for the AIDS/ACMS features: archground requirements. As a consequence, no specification reports is available. This means that the format of the producedin advance. Saying there are as many formats as operators woa caricature but not that much.

Therefore, no automatic data collection for fully automated aimonitoring purpose is available for A300/A310/A300-600 aircraftOn the operator’s side, the alternatives are:- To manually observe the cruise phases. In that case, s

stability criteria must be taken into account,




4.3. A320 family/A330/A340 aircraft

4.3.1. Introduction

The analysis requires many parameters for one reflight data set. Each in-flight data set is like a snthe aircraft conditions. As many records as possibe obtained to increase the reliability of the results.

This chapter will provide an overview of the various aircraft recording sythe way to retrieve the information.

The Aircraft Recording and Monitoring Systems are basically divided categories:1. The Centralized Fault Display System (CFDS)2. The Flight Data Recording System (FDRS)3. The Aircraft Integrated Data System (AIDS) for the A320 family airc

Aircraft Condition Monitoring System (ACMS) for A330/A340 aircraft

The FDRS and AIDS/ACMS systems are devoted to collecting somparameters. The following diagram sums up the functions of both systemcases, the feedback from the aircraft allows the operators to take the aactions.

OperationalRecommendation

FDRS

IInncciiddeenntt AAcccciiddeen

IInnvveessttiiggaattii

EEnnggiinnee CCoonnMMoonniittoor r iinn

AAPPUU

HHeeaalltthh

MMoonniittoorrii

ProcessedData

H OW TO REC



Only the AIDS/ACMS system is described in the following as it

system to collect data for automatic processing thanks to the AP

4.3.2. Aircraft Integrated Data System (A320 Family Condition Monitoring System (A330/A340 ACMS)

With the integration of modern state-of-the-art technology like t

the Full Authorized Digital Engine Control (FADEC), the complesystems led to the development of the Aircraft Integrated Data SWhile the FDRS is intended to assist operators in case of incidemain objectives of the AIDS/ACMS are more of a preventive nat

Long term trend monitoring of the aircraft performance really frame of maintenance actions and is complementary to all other on the engines or the APU.

4.3.2.1. The AIDS/ACMS functions

AIDS/ACMS is used to monitor the aircraft systems mainly theand the aircraft performance in order to perform preventconsequence, it will enable operational recommendations to be f

The AIDS/ACMS main functions are described in the picture belo




4.3.2.2. How AIDS/ACMS is implemented

The AIDS/ACMS is mainly interfaced with the Data Management UnitFlight Data Interface and Management Unit (FDIMU). Depending on tconfiguration, DMU or FDIMU may be fitted on the aircraft.

Basically, the FDIMU is a hardware combining the DMU and FDIU. Onmanagement part of the FDIMU will be considered in the following.

The DMU/FDIMU is a high-performance avionics computer specializacquisition of ARINC 429 Digital Information Transfer System (DITS)associated processing. All tasks are performed in real time. The DMUthe central part of the AIDS/ACMS and may be reconfigured via thSupport Equipment tools of the operator.The DMU/FDIMU interfaces with other aircraft systems such as the F ADIRU. Approximatively 13000 parameters are fed into the DMU/FDIMU

AAIIDDSS / /AACCMMSS ddaattaa ssoouur r cceess

((uupp ttoo 4488 AARRIINNCC 442299 bbuusssseess))

Solid State Mass Memory (SSMM) for reports & SAR data (raw data in compressed form) storage

AAIIDDSS / /AACCMMSS DDMMUU

CFDIU(BITE)

H OW TO REC



4.3.3. Generic functions of the DMU/FDIMU

Based on these parameters, the DMU/FDIMU performs several t- It processes incoming data to determine stable frame c

monitor limit exceedances,- It generates reports according to specific programmed trigge- Associated with a ground tool, the DMU/FDIMU is very flexib

programmed by the operator.

4.3.3.1. The Airbus standard reports

One of the generic functions of the DMU/FDIMU is the generengine reports as a result of specific events defined by triggeringThe Airbus Standard Reports are a set of pre-programmed AIwhich are operative at delivery of the DMU/FDIMU.These reports have been defined and validated by Airbus. Th

aircraft type (A320 family or A330 or A340) and on the engine ty

Here are all the reports available:

For Aircraft Performing Monitoring- Aircraft Cruise Performance Report (02)

For Engine Trend Monitoring- Engine Take-Off Report (04)- Engine Cruise Report (01)- Engine Divergence Report (09)

For Engine Exceedance Monitoring- Engine Start Report (10)- Engine Gas Path Advisory Report (06)

- Engine Mechanical Advisory Report (07)

For Engine Trouble Shooting- Engine Run up Report (11)- Engine On Request Report (05)


Wh t (06) (07) (09) (14) (15) (19) t ti ll



When reports (06), (07), (09), (14), (15) or (19) are automatically maintenance and investigative actions are required.

Most of these reports allow a change in the trigger limits or in the lenreport. In addition, user specific trigger conditions can be created for eusing the Ground Support Equipment tool (see below).

The reports are described in the relevant Aircraft Maintenance Manual, s36-00 or in the Technical Description Note provided at the aircraft delivDMU/FDIMU system manufacturer.

4.3.3.2. DMU/FDIMU transfer file interfaces

The DMU/FDIMU provides various communication interfaces for operatoand ground communications. The usage of these communication cmostly programmable. For instance, reports can be printed out or, tran

the ground via ACARS or retrieved on a floppy disk via the airborne d(MDDU).This means that each operator can set up the DMU/FDIMU to mostsupport the airline specific data link structure.The picture below shows different data flows from the aircraft operations. All interfaces are then described one by one.

AAIIDDSS / /AACCMMSS

FFDDIIMMUU / /DDMMUU

DAR (option)

RRaaww

ddaattaa

Dumping fromDMU memory

via theMDDU

Dumping from



- an optional Digital AIDS/ACMS Recorder (DAR)

The DMU/FDIMU data can also be stored on an optional recorder: the DRecorder (DAR). It is a magnetic tape cartridge or an optical disk. Tavailable for aircraft equipped with Teledyne DMU/FDIMU. The retrievcan be:- manually initiated (via the MCDU) recording of reports- automatic

- a Smart Access Recorder (SAR) An integral part of the DMU/FDIMU is the optional Smart Access RecorIt is used to store flight data. Sophisticated data compression algorithmsefficient usage of the limited DMU/FDIMU memory (Solid State MassSSMM). To read out the SAR data, the operator can use a diskette via tor a PCMCIA card via the PCMCIA interface.The data from the SAR storage buffer can be retrieved through the airbloader.

To manually initiate some specific reports, a remote print button is locapedestal in the cockpit. The report/SAR channel assignment of the rebutton is programmable via the Ground Support Equipment (see below).

- An optional PCMCIA card (A320 FAM aircraft only)The integrated PCMCIA interface can store the AIDS/ACMS standard rstore data via the PCMCIA interface, a PCMCIA card in MS-DOSrequired.

The advantage of the PCMCIA card is that the time to access the medlower than when using a floppy disk in the airborne data loader.The PCMCIA card can be connected to a Personal Computer to dump thfurther analysis.

- An optional ATSU (ACARS function).For those aircraft equipped with the Aircraft Communication and

System, it is possible to send the AIDS/ACMS reports directly on the grformat of the reports is different from the ones that can be retrieved dithe DMU/FDIMU (see above) because every transmission costs money.

This system is essential for engine and aircraft monitoring of importan

H OW TO REC



Printer

MCDU




4.3.3.3. Example of manual triggering downlink

Manual triggeringand downlink of reports

Downliautoma

triggerereports

AIDS MAN REQ REP

SEND (←DUMP SEND→)* CRUISE 01

* A/C PERFORMANCE 02

* TAKE OFF 04

* ON REQUEST 05

* GAS PATH ADVISORY

<RETURN PRINT*

↑↓ SCROLL ←→ SELECT

AIDS STORED REP

SEND (←DUMP SE* CRUISE 01 DNLKD LEG 00 PRINTED* A/C PERFORMANCE 02 LEG 00 PRINTED

* TAKE OFF 04 LEG 01 PRINTED* ON REQUEST 05 DNLKD LEG 02 PRINTED* GAS PATH ADVISORY DNLKD LEG 02<RETURN PR

↑↓

AIDS

< PARAM LABEL PARAM ALPHA >

< DMU PROG/DOC PREV REP >

< SPECIAL REP

RUN STOP * MAN REQ REP STORED REP

< SEND/PRINT SEND/PRINT

H OW TO REC

4.3.3.4. Summary



y

The AIDS/ACMS reports can be:- printed out on the cockpit printer in flight or on ground,- collected by retrieving the PCMCIA card,- downloaded on ground only from the DMU/FDIMU memo

using a floppy disk or via the PCMCIA interface to a PCMCIA- downloaded through ACARS in flight or on ground.

4.3.4. The Ground Support Equipment (GSE)

For the individual programming of the DMU/FDIMU functions, tprogrammable either with the assistance of an AIDS/ACMSthrough the MCDU (very limited). The GSE is a software DMU/FDIMU manufacturer. The GSE is under airline respons

4.3.4.1. AIDS/ACMS reconfiguration tool

The tool can be used:- to program trigger conditions, processing algorithms, layout

and the DAR & SAR recording format.- to configure the AIDS/ACMS DMU/FDIMU database- to create user programmable reports, sophisticated aircraft m

collection functions.The program is loaded into the DMU/FDIMU on ground using

PCMCIA card

4.3.4.2. AIDS/ACMS readout tool

It allows the operator to view the reports.

4.3.4.3. Data processing analysis

Once the in-flight data have been retrieved, they can be proceswith the APM program.




4.3.4.4. Example of SFIM GSE – Triggering condition program

4.4. The Cruise Performance Report

In brief, the recording systems described above produce a series of repthe Cruise Performance Report or DMU/FDIMU report number <02> (CP

of interest for aircraft performance monitoring.The present paragraph describes this particular file and may be considreference.

H OW TO REC



The CPR<02> can be obtained:

- on a piece of paper via a printout on the cockpit printer - in digital format (on a diskette, on the DAR optical disk (A33

PCMCIA card (A320 FAM aircraft only) or via transmission by

The advantages of automatic recording are that::- all data required for cruise performance analysis are store

format- the report in digital format can be used “as is” without any a

operations. When the report is not in a digital format, operations as in case of manual recording will have to be don

4.4.2. Two report formats

There are actually two different formats of CPR<02> files d

DMU/FDIMU interface used for report retrieval.

4.4.2.1. Printed report, diskette or PCMCIA dumped re

These reports have the following format.

Reports have standard header comprising:- Three lines programmable by the airlines- Report identification (name and number)- Documentary data identifying aircraft,DMU and summarizing report trigger conditions

Body of the report defined by the reporttype and will contain data relevant toeach report


4 4 2 1 1 E l f CPR<02> f A319 i ft fitt d



4.4.2.1.1. Example of CPR<02> for an A319 aircraft fitted

controlled Engines


A/C DATE UTC FROM TO FLT

CC AI-001 feb99 113412 LFBO LFBO 05080

PH CNT CODE BLEED STATUS APU

C1 06 00514 5000 48 0010 0 0100 48 0

TAT ALT CAS MN GW CG DMU/SW

CE N240 33000. 276 780 6500 330 I51001CN N240 33000. 276 780 6500 330 I51001

ESN EHRS ECYC AP QA QE

EC 0100003 03000 00600 71 12 12

EE 0100004 03000 00600 71

EPR N1 N2 EGT FF P125

N1 1284 8321 8320 3580 1283 06892

N2 1284 8320 8321 3580 1283 06892

P25 T25 P3 T3 P49 SVA

S1 11155 0557 1243 4313 06150 069

S2 11137 0556 1231 4324 06142 068

BAF ACC LP GLE PD TN P2 T2

T1 094 082 00 035 40 180 04219 N255

T2 096 082 00 023 36 180 04215 N271

ECW1 ECW2 EVM OIP OIT OIQH

V1 03D01 00008 08000 245 121 0000

V2 03D01 00008 08004 234 120 0000

VB1 VB2 PHAV3 024 005 043

V4 007 001 078

WFQ ELEV AOA SLP CFPG CIVV

X1 02652 N003 0025 0000 N0001 0001

X2 02772 N001 0025 0000 N0000 0003

RUDD RUDT AILR AILL STAB ROLL YA

X3 0000 0008 N001 N006 N008 N000 N00

RSP2 RSP3 RSP4 RSP5 FLAP SLAT

X4 N000 0000 0000 0000 0000 0000X5 0000 0000 0000 0000 0000 0000

THDG LONP LATP WS WD FT FD

X6 1905 E0019 N450 050 011 0110 XXXX

X7 XXXX E0019 N450 050 011 0108 0785

H OW TO REC



4.4.2.1.2. Example of CPR<02> for an A319 airc

controlled Engines


A/C DATE UTC FROM TO

CC AI-001 feb02 110117 LFBO LFBO

PH CNT CODE BLEED STATUS

C1 06 00514 5000 48 0010 0 0100 48

TAT ALT CAS MN GW CG

CE N240 33000. 276 780 6500 33

CN N240 33000. 276 780 6500 33

ESN EHRS ECYC AP QA QE

EC 0100003 03000 00600 71 12 12

EE 0100004 03000 00600 71

N1 N1C N2 EGT FF PS

N1 868 869 875 5850 1320 06

N2 868 869 875 5850 1320 06

P25 T25 P3 T3 P49 SV

S1 11155 0557 1243 4313 06150 06

S2 11137 0556 1231 4324 06142 06

BAF ACC LP GLE PD TN P2 T2

T1 094 082 00 035 40 180 04219 N2

T2 096 082 00 023 36 180 04215 N2

ECW1 ECW2 EVM OIP OIT OIQH

V1 03D01 00008 08000 245 121 0000

V2 03D01 00008 08004 234 120 0000

VB1 VB2 PHA

V3 024 005 043

V4 007 001 078

WFQ ELEV AOA SLP CFPG CI

X1 02652 N003 0025 0000 N0001 00

X2 02772 N001 0025 0000 N0000 00

RUDD RUDT AILR AILL STAB RO

X3 0000 0008 N001 N006 N008 N0

RSP2 RSP3 RSP4 RSP5 FLAP SL

X4 N000 0000 0000 0000 0000 00

X5 0000 0000 0000 0000 0000 00

THDG LONP LATP WS WD FT F



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Report output APM input Remarks C



Report output APM input Remarks C

BLEEDSTATUS“

APU

WBLLWBLR

FLHV

Left engineRigh engine

Eg. 99 0100 0 0010 99

Eg. 1

not on report.

99 LH Pa

LH Wing A

Eng1 NAC

Eng 1 PR

Eng 1 HP

Cross Fee

Eng 2 HPEng 2 PR

Eng 2 NA

RH Wing

99 RH Pa

Apu bleed

4.4.2.2. Report transmitted by ACARS

As ACARS transmissions are expensive, when the CPR<02> isground, the format of the received file is slightly different so alength of the file and its size.

The sample file below is an example of ACARS transmissiopoints recorded for the same aircraft registered AI-002.

- A02/A32102,1,1/CCAI-

002,APR11,153333,EFOU,EFHK,0368/C106,34201,5000,54,0010,0

3,31019,290,782,7080,242,C73001/CNN171,31053,290,783,7080

208,00256,00165,73,33,22/EESN0002,00208,00260,00165,73/N1

947,1428,07947/N20844,0845,0929,5888,1443,07827/S115521,0

80,020,006/S215528,0713,1531,4308,4019,018,002/T1099,096,

6271,0336/T2099,096,023,46,036,06335,0305/V105,00,287,168

2,02,135,105,01,00,00000/V3XX,XX,XXX,XXX,XXXX/V4XX,XX,XXX

1,283,046,0916/V612,02,182,268,0916/V7044,083,00081,22222

082,00061,22222222222111/X102541,N002,0017,0000,00000,000

014,0000,00000,N000/X3N000,0004,N006,N007,N006,N002,N000/X


The correspondence between this file and the standard report can be otracking the lines identifiers For instance the aircraft registration is id



tracking the lines identifiers. For instance, the aircraft registration is id

A/C in the standard report. It is written on line CC.In the ACARS-transmitted file, the first characters are:- A02/A32102,1,1/CCAI-002 […]Each data is separated by a comma “,”. After a slash “/”, the line idwritten. So in this record, we can read AI-002 is the aircraft registration.

4.4.2.3. Report specification

Both Print-like report and ACARS report have been defined in accorda

specification.

The exhaustive description of the print-like file is given to the operators part of the Airbus documentation, the Aircraft Maintenance Manual section 31-36-00. Read Chapter H-Appendix 5 – AMM extracPerformance Report <02> description.

As far as the ACARS format is concerned, no specification is made athe customers. Airbus is ready to provide such a description of the ACAupon request.

4.4.3. The trigger logic

A trigger logic is a set of conditions checked before the DMU/FDIMU gereport.

There are several trigger logics for the cruise performance report example, one is for the manual selection via the MCDU; another one is of the remote print button as an order for the data collection.In particular, trigger logic n°5000 (or 4000 depending on the aircraftcalled the best stable frame report logic. This trigger logic aims at detecflight conditions in order to avoid report triggering in flight phasparameters are of no use.

Airbus recommends the use of these reports for aircraft performance-purposes.

The AIDS/ACMS Cruise Performance report <02> is generated DMU/FDIMU detects that the conditions defining a stable cruise are m

H OW TO REC

An aircraft quality number characterizes each report. It is defbelow formula:



below formula:

∑ ×= 2)()()(

N TOL N VAR N W QA

where N is parameter number N (can be the N1, fuel flowW(N) is a weighing factor (between 0 and 1)VAR(N) is the individual varianceTOL(N) is the individual variation value

The lower the quality numbers the better the stable frame between 0 and 999. Common values seen in routine monitoriThe quality numbers are not used as a trigger condition but are best report during a searching period.The operators can use it so as to eliminate possible irrelevant rthe time, quality numbers are not used because it is hard toespecially for short-range flights.

Example of trigger logic and conditions for an A320 aircraft fittedThe DMU/FDIMU generates the CPR<02> based on flight hourschoice is programmable via the GSE.Depending on the basis for searching, the DMU/FDIMU searchfor report generation with stable frame criteria where the benumber is calculated. The report with the best quality number is

report buffer.

The basic DMU/FDIMU configuration for the A320 aircraft is:1. Searching time frame: 1 hour 2. Observed data during five sub-periods of 20 seconds each.

retained thanks to the quality number.3. The stability criteria, which must be met are:

Parameter Limit

Inertial Altitude 150 feet

Ground Speed 6 kt

Roll Angle 0 8 degrees


4.5. Data analysis procedure

Th l i d i h i l d t th h



The analysis procedure is much simpler compared to the case when

manual recordings because the stability criteria were already checkDMU/FDIMU before parameters are recorded. As of a consequence, assessment of the parameter stability is required.

All the input data were stored in the Cruise Performance Report <02> apfew parameters that are given down below:

- The fuel Lower Heating Value: as this value cannot be read in thmust be obtained from another source. When performing an ausample will be analyzed and the corresponding FLHV will be identifieof routine performance monitoring, the FLHV will be assumed estandard value. Most commonly, the value 18590 BTU/LB is used foYet some precautions have to be taken, in order not to bias the different fuel factors (see Chapter F-Using monitored fuel factor ).

- The year of recording may not be stored in reports for some aircraftyear should then be provided for the analysis and for history purpose

- When the parameters are automatically recorded thanks to the DMnon relevant points are simply eliminated (for instance, points recorded below FL200 are not taken into account). It may happenpoints are recorded due to DMU/FDIMU malfunctions. As a con

particular attention is required so as to assess the validity of eachpoint. This check is often performed when a discrepancy in performance analysis is noticed on a few points.

The analysis of the resulting points can be performed with an Airbus spbased on the specific range method: the APM program. Airbus has implspecific routine that allows automatic loading of cruise performancnumber 02, when in digital format.

Statistical elimination can be selected before the actual analysis withprogram. For each parameter (fuel flow, N1/EPR,…), the mean valustandard deviation is calculated over all the records. The user can therecords so as to get rid of inappropriate low quality readings

C RU

D CRUISE PERFORMANCE ANALYSIS



D. CRUISE PERFORMANCE ANALYSIS

Several Airbus tools are available to perform cruise performa Airbus Aircraft Performance Monitoring (APM) program comeaircraft performance monitoring due to the amount of data to proprogram features a DMU/FDIMU report loading function, whtedious handling operations.

Some other Airbus tools (the IFP program…) are available for thmay be used. The tool choice is at the airline's discretion.

The following lines deal with the software aspect of cruise perfThe pre-requisite for this chapter is a basic comprehension parameters from the aircraft, as well as general background onmethod itself.

1. THE BOOK LEVEL

As a reminder, the aircraft performance book level is establishmanufacturer and represents a fleet average of brand new airThis level is established in advance of production and is deriveNormal scatter of brand new aircraft leads to performance abobook value. The performance data given in the Airbus documenOperating Manual) reflects this book value.

The high-speed book value data is stored in the high-spdatabases used by Airbus performance software such as the IF APM programs. This aircraft Performance model is built baseextensive performance flight tests: the IFP model.Most of the Computerized Flight Plan systems as well

Performance tables in the Flight Crew Operating Manual aReference Handbook use the IFP model.

2 A TOOL FOR ROUTINE ANALYSIS : THE APM PROG

C RUISE PERFORMANCE ANALYSIS

It calculates the deviation of flight parameters such as fuel flow, anengine parameters from nominal book values. The end result is a de



range, which reflects how far the aircraft is from its book value.The specific range can of course be worse but also better than the because this book level only represents an average performance levnumber of brand new aircraft/engine combinations.

The delta specific range is the monitored fuel factor (opposite sign), allow the operator to tune:- the aircraft FMS flight plan on board the aircraft,

- the computerized flight planning and every high-speed performanstudies in maintenance servicing, engineering or dispatch of the aircr

2.2. Basics

The APM calculates aircraft cruise performance in a so-called determiThat is with the use of mathematical methods from the fields of probabil

estimation or filtering techniques and by using familiar equations of liftengine thrust in stabilized conditions during cruise. The analysis is Specific Range method. For each flight case, in flight recorded data calculate a measured Specific Range (SR, distance covered per unit of fResults are then compared to the SR that is predicted for the gconditions (weight, altitude, TAT, Mach) based on a theoretical model.which, the program determines a deviation in specific range. Furthermoenables a distinction between airframe and engine influence.By comparing book and measured values of engine power setting, fueexhaust gas temperature, a set of deviation parameters is being calculproduced in a result file.

The APM program schematically works as described in the followingOrange boxes represent the theoretical model, blue boxes represent act

Airframe EnginePoint

of Cruise

THEORETICALN1

Theoretical FF

Apparent Airframecontribution

C RU

The input file contains information about Mach number, altitgross weight, CG location, bleed flow, FPAC (Flight Path A



(Inertial Vertical Velocity).

2.3. The input data

This paragraph details the input, which the APM program performance analysis.Following is a reference table for cross-checking that all require

be accessed easily.

s u l t



U n i t

C o m m

e n t s

I n f l u e n c e o n t h e r e

s

( – )

N o n e

Y Y M M D D

N o n e

( – )

N o n e

1 - 9 9

N u m b

e r o f d a t a o f a s a m

e f l i g h t . I f n o v a l u e

i s s e t ,

t h e p r o g r a m s e t s a

" 1 " .

N o n e

g t i m e

h h m m

T i m e

a t w h i c h t h e p e r f o

r m a n c e p o i n t w a s

t a k e n

i n f l i g h t .

N o n e

( – )

N o n e

( f t )

F r o m t h e t w o a i r d a t a c o m

p u t e r s ( A D C )

( – )



e

( ° C )



( k g o r l b )

I m p a c t o n D F F A

( % )


o n

( g )

H o r i z o

n t a l a c c e l e r a t i o n m e a s u r e d i n g .


( f t / m i n )

V e r t i c a l a c c e l e r a t i o n

( ° )

O p t i o n

a l - u s e d

o n l y i f

g r a v i t y

c o r r e c t i o n

a c t i v a t e d .

( ° )

O p t i o n

a l - u s e d

o n l y i f

g r a v i t y

c o r r e c t i o n

a c t i v a t e d .

( k t )

O p t i o n

a l - u s e d

o n l y i f

g r a v i t y

c o r r e c t i o n

a c t i v a t e d .

( ° )

O p t i o n

a l - u s e d

o n l y i f

g r a v i t y

c o r r e c t i o n

a c t i v a t e d

R M A N C E A N A L Y S I S

s u l t

F F i s r e c o m m e n d e d

n

f o r p e r f o r m a n c e

n g .



C R U I S E P E R F O R

( k g / h , l b / h )

F u e l f l o w f o r e a c h e n g i n e

( F F A 1 , F F A 2 , . . . )

I m p a c t o n D F F B

U n i t

C o m m

e n t s

I n f l u e n c e o n t h e r e

s

t u r e

( ° C )

T o b e

s e t f o r e a c h e n g i n e

( E G T 1 , E G T 2 , . . . )

u e

( B T U / l b )

I m p a c t o n D S R

t )

( k g / s

o r

l b / s )

E n g i n e 1 f l o w

( t w i n e n g i n e A / C ) o r s u m o f

e n g i n e s 1 a n d 2 ( 4 e n g i n e

- a i r c r a f t )


h t )

( k g / s

o r

l b / s )

E n g i n e 2 f l o w

( t w i n e n g i n e A / C ) o r s u m o f

e n g i n e s 3 a n d 4 ( 4 e n g i n e

- a i r c r a f t )


L a n d

( – )

0

. . .

o f f ( n o b l e e d

)

E

. . .

e c o n o m i c ( l o w )

N

. . .

n o r m a l

H

. . .

h i g h ( m a x )


A C N O R M

/ A I O

F

b l e e d

c o n f i g u r a t i o n

m o n i t o r i n g r e c o r d i n


2.4. APM output data



Before detailing the APM output data, the following lines will remind the pthe Airbus APM program.

Figure D2 – Principle of the APM program calculation

Based on the flight mechanics equations, and thanks to some of the precorded in-flight, it is possible to determine the amount of lift or lift coeffThe aerodynamic characteristics of the aircraft are known from the IFP mdrag to lift relation and the calculated lift allows to get the correspondingdrag (CD).In the flight mechanics equation, the drag is the required thrust to ma

flight. The thrust at N1 (in the example) is deduced from the IFP enggiving us the N1 as per the book level or theoretical N1 (N1TH).

Second, at a given N1, the IFP model allows us to determine what the fTh f l fl di t th d N1 (N1A) i ll d th C

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The APM output file also provides average figures for the two (o



. DFFAM = (FFCM - FFTH) / FFTH x 100 (%). DFFBM = (FFAM - FFCM) / FFCM x 100 (%)

. DSR = (FFTH - FFAM) / FFAM x 100 (%).

DSR represents global aircraft performance degradation (inSpecific Range degradation.

DFFB is the deviation of fuel flow due to engine deterioration.

DFFA is the deviation fuel flow due to "apparent" airframe deterio

Some aspects need to be underlined to better appreciate reprogram:

DFFB is only linked to N1/EPR and FF recordings, and is indepthrust relationship and of the associated engine model. This mlevel of confidence can be given to the DFFB value.

DFFB is also linked to the fuel lower heating value (FLHV). Tvalue is 18590 Btu/lb. The FLHV is used to calculate theoreticaas the fuel flow (FFTH), the N1/EPR (N1TH/EPRTH).

DFFB is also linked to the calibration of the engine fuel-flow met

DFFB results can be confirmed by a separate EGT analysis engine maintenance specialists in the airline.

DFFA is linked to flight conditions. Flight conditions are the maespecially inaccurate aircraft gross weight (payload based on and non-negligible FPAC. Therefore, the DFFA value needs to

the utmost precaution.

In other words, a high DFFA does not necessarily indicate a deterioration of the airframe. An altered EPR/thrust relatio


2.5. The APM statistical analysis



The aim of this paragraph is to give a reminder and some explanations ostatistics were implemented in the APM program.

2.5.1. General

The APM program features a statistical elimination of measurement poinoutput results DN1/DEPR, DFFA, DFFB, and DSR, the mean valu

standard deviation are calculated.

Whenever any point of measurement result is outside the 95 %

confidence (µ - 2 σ, µ + 2 σ) it is eliminated (replaced by a trailing "*

included in the relevant parameter mean value and standard deviation.

A low standard deviation value provides a high level of confidence, sincthat all results are consistent and within a limited range.

2.5.2. Mean value (µ)

The simplest statistic is the mean or average. It is easy to calculate avalue and use that value as the "target" to be achieved.

The mean value characterizes the "central tendency" or "location" of

Although the average is the value most likely to be observed, many of values are different from the mean. When assessing control materials, itthat technologists will not achieve the mean value each and every time being performed. The values observed would show a dispersion or daround the mean, and this distribution would need to be characterizerange of acceptable control values.

2.5.3. Standard deviation (σ)

The dispersion of values around the mean value is predictable ancharacterized mathematically through a series of steps, as described be

1. The first mathematical manipulation is to sum () all individual p

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4. Finally, the predictable dispersion or standard deviation (σ)

as follows:



)1(

)( 2

−−

= ∑n

x x iσ

where xi measurement number i

x mean value of all the measuren number of measurement point

2.5.4. Degrees of freedom

The "n-1" term in the above expression represents the degLoosely interpreted, the term "degrees of freedom" indicates howindependence there is within a group of numbers. For example, four numbers to get a total, you have the freedom to select anyHowever, if the sum of the four numbers is supposed to be 92first 3 numbers is fairly free (as long as they are low numbers),

is restricted by the condition that the sum must equal 92. For ethree numbers chosen at random are 28, 18, and 36, these numwhich is 10 short of the goal. For the last number there is no fThe number 10 must be selected to make the sum come out to degrees of freedom have been reduced by 1 and only n-1 deremain. In the standard deviation formula, the degrees of freedbecause the mean value of the data has already been calculateone condition or restriction on the data set).

2.5.5. Variance

Another statistical term that is related to the distribution is the

the standard deviation squared (variance = σ² ). The STAND

may be either positive or negative in value because it is calcuroot, which can be either positive or negative. By squaring

DEVIATION, the problem of signs is eliminated. One commonvariance is its use in the determination whether there is a statdifference in the imprecision between different methods.

In many applications (especially in the APM program)


The normal distribution is a continuous probability distribution, which characterize a wide variety of types of data. It is a symmetric distribut



y yp ycompletely determined by its mean and standard deviation. The normal dis particularly important in statistics because of the tendency for samplefollow the normal distribution.

The figure hereafter is a representation of the frequency distribution of of values obtained by measuring a single control material. This distribut

the shape of a normal curve. Note that a "gate" consisting of ±1 σ ac

68% of the distribution or 68% of the area under the curve, ±2 σ accounand ±3 σ accounts for >99%. At ±2 σ, 95% of the distribution is inside th2.5% of the distribution is in the lower or left tail, and the same amounpresent in the upper tail. This curve is like an error curve that illustrateserrors from the mean value occur more frequently than large ones.

Figure D3 – Gaussian distribution law

The normal distribution is also known as the Gaussian distributioinceptor, Johann Carl Fredirich Gauss.

2.5.7. Confidence interval

A confidence interval is a statistic constructed from a set of data to

µ

68%

- 1 σ + 1 σ- 2 σ + 2 σ

95%

Number of

events

value

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2.6. The APM archiving system

The APM program enables the storage of ai



data in libraries for long term trend monitorinBoth input data coming from measurementissued from the analysis can be stored in libenables to monitor the aircraft degradation

as to identify any corrective actions to be taken. It also enablesresults over all the tail numbers of the fleet. A nice-handling interface provides an efficient and proper datathese so-called APM libraries.

2.7. Some nice-to-knows about the APM

To determine the aircraft performance level with accuracy, a parameters must be recorded prior to take off and in-flight.

2.7.1. Influencing factors

Chapter B-Background introduced to the aircraft performance mand reminded the possible causes for bias and/or scatter on the

The APM program has evolved over the past twenty years soautomated correction calculations to take into account part factors.

Amongst these, the Coriolis effect is taken into account. Enposition and heading will make the influence calculated automat

An energy correction is included to the APM to take into acckinetic (FPAC – acceleration / deceleration) and potential enevertical velocity). The energy variations due to horizontaaccelerations are taken into account through the values recorpath acceleration, inertial vertical velocity). This reduces the sresults but is only valid for small movements around the respecting the stabilization criteria. It boils down to remain in thethe equations of movement programmed into the APM.


2.7.2. Aircraft bleed configuration

The APM program can use DMU cruise performance report n

(CPR 02 ) i t fil O f th t i hi h i i d b



(CPR<02>) as an input file. One of the entries, which is required byprogram, is the bleed flow for each pack. The cruise performance contains the pack bleed flows.

As far as the bleeds are concerned,- No cruise performance report is produced whenever the configuratio

required: anti ice OFF, cross feed valve open, symmetrical valve pos- A given record is not analyzed whenever the recorded difference bet

flow 1 and pack flow 2 is higher than 10%.

Focusing on the second item, the following is worth mentioning it.

The bleed flow asymmetry has an impact on the theoretical fuel flow (F APM program must use the mean value of left and right bleed flows to FFTH. A 10%-margin was retained so as to avoid error in calculating

greater than 0.1%. More precisely, when the data is read from a CPRbleed flow is defined by pack left/right flows. The APM program cope two values by:- averaging both values to get a single value,- reading in the engine high speed database the related fuel flow by inbetween two bleed ratings (OFF, LO/ECON, NORM, HI).

In practice, bleed flows between both packs can be different. This ite

significant on A320 aircraft types, where the old standard of Flocomponents (including flow control valves) had a less restrictive tolerance than the newer standard. Airbus published a specific Service ILetter (SIL) to inform airlines of this issue. This SIL is given in Ch Appendix 4 – Airbus Service Information Letter 21-091.

The APM program will evidence that some troubleshooting may be rethis specific ATA 21 item. The Trouble Shooting Manual (TSM) containof entries in the form of crew observations in section 21-51. The procelead relevant trouble shooting procedures.

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(B) with the possibility of engine-to-engine model alteration relationship).



2.7.3.2. Engine-to-engine model N1 (EPR) / thrust relalterations whereby DFFA – aerodynamic part – (quadrant may

An observed ∆N1 or ∆EPR does not necessarily indicatedeterioration of the airframe. An altered N1 /thrust or EPR / thrusrespect to the reference engine is, in many cases, respo

deviation. This is also valid for new engines as well. Engine tesor EPR versus thrust ratios cannot be transmitted to cruise altitude conditions with an acceptable confidence level.

Figure D4 – Illustration of the thrust at N1/EPR uncertainty

2.7.4. Processing ruleThe recorded data are processed considering the following rmandatory parameters is missing, an average value will be takto run the APM program, but the final result will be biased a

N1 meas : N1 measured on the aircraft DSR = (FFA - FF th ) / FF th (%) (overal

FFA : fuel flow measured on the aircraft DFFA = (FFC-FF th) / FF th (%) (thrust/

FFC = FF (N1 meas) via the engine model DFFB = (FFA - FFC) / FFC (%) (engine

FF th : provided by the overall aircraft model

FUEL FLOW

THERMODYNAMICS

N1

CL (Lift)

N1 th

FF th

N1 meas

FFCFFA

DSR DFFA

DFFB

Mach number, Altitude, TAT

Aircraft weight, CG position

FPAC, IVV, Bleed flow

}


3. HOW TO GET THE IFP & APM PROGRAMS

Th APM i t f th P f E i ’ P k (PE



The APM program is part of the Performance Engineers’ Package (PEincludes a number of performance software.The package is available for all Airbus aircraft types and can be cdepending on individual needs.

It can run on many computer platforms to satisfy the airlines’ particuThese platforms are:

- Personal computers equipped with Microsoft Windows- Mainframes (IBM-MVS/VM systems…)- Unix workstations

The PEP is a software mostly used by airlines’ Engineering andOperations. Airbus Flight Operations & Line Assistance department is refor the dispatch and the maintenance of this software. The contact addreis:

CUSTOMER SERVICES DIRECTORATEFlight Operations & Line Assistance - STL

1, rond point Maurice BellonteBP33

E. RESULTS APPRAISAL



1. INTRODUCTION

This chapter deals with the way to relate the results of the canalysis to a practical interpretation and gives hints at undersapparent deterioration that is measured on an aircraft may csome cases, gives recommendations to actually improve the airc

The following is focusing on results obtained with the APM prequisite for this chapter is a good knowledge of the APM proutput data that it can produce. More details on that subject arD-Cruise performance analysis.

As a reminder, the APM output data are:

- DSR represents aircraft performance degradation (in %), inRange degradation.

- DFFBx is the deviation of fuel flow due to the engine denumber x).

- DFFAx is the deviation of fuel flow due to the "apparent" airf(DFFAx is equivalent to a delta of drag) linked to engine num

- DN1x (resp. DEPRx) is the deviation of N1 (resp. EPR) for emaintain flight conditions.

2. INTERPRETING THE APM OUTPUT DATA

As a reminder, the purpose of the APM program is to compareperformance level versus the book level. The following lines conclusions when interpreting the output data.

Figure E1 reminds the APM principle.

R ESULTS APPRAISAL



Figure E1 - APM principle

The above figure proves that a positive N1/EPR deviation results in DFFA.

2.1. DFFA interpretation

Case 1 - DN11 and DN12 >0 and thus DFFA1 and DFFA2 >0DFFA> 0, i.e. higher apparent drag or lower thrust at N1than model

Case 2 - DN11 and DN12 <0 and thus DFFA1 and DFFA2<0DFFA<0 i.e. lower apparent drag (or higher thrust at N1) than model

2.2. DFFB interpretation

Case 1 - DFFB1 and/or DFFB2>0

2.3. DSR interpretation

Combining paragraphs 2.1 and 2.2 gives the following possibil

specific range deviation



specific range deviation.

Case 1 - DFFA > 0 and DFFB > 0 ⇒⇒⇒⇒ DSR < 0Compounded effect resulting in specific range deviation (worse t

Case 2 - DFFA < 0 and DFFB > 0

1) if DFFA > DFFB ⇒ DSR > 0

Higher engine fuel consumption than model is being comapparently better than nominal aerodynamic condition resultingrange than book value

2) if DFFA < DFFB⇒ DSR < 0Partial compensation of resulting in worse specific range than bo

Case 3 - DFFA > 0 and DFFB < 0:

1) If DFFA < DFFB ⇒ DSR < 0Partial compensation of resulting in worse specific range than bo

2) if DFFA < DFFB ⇒ DSR > 0 An apparently worse than nominal aerodynamic condition is b

by lower engine consumption than model, resulting in better sbook value.

Case 4 - DFFA < 0 and DFFB < 0 ⇒⇒⇒⇒ DSR > 0Compounded effect resulting in specific range deviation (better t

R ESULTS APPRAISAL

3. EXAMPLE

This paragraph is based on a cruise performance analysis that was per



This paragraph is based on a cruise performance analysis that was peran A310-304 fitted with CF6-80C2A2 in year 1990.

Figure E2 shows manual readings that were taken at that time. The thpoints identified from the manual recordings of Figure E2 were processeOnly two of these were retained by the statistical procedure and areFigure E3.

The result of DFFA and DFFB (with DFFA < 0 and DFFB > 0 and DFFA

a marginal deviation in DSR (-0.56%). Higher engine fuel consumption tis very often observed and at times is partially compensated by an better than nominal aerodynamic condition as exemplified in the APshown in Figure E3.

Figure E2 - Example of manual recordings



R ESULTS APPRAISAL

4. REMARKS

A few remarks are given below, based on the feedback Airbus has haoperators. Any suggestion or comment on this part is welcome. Thes



operators. Any suggestion or comment on this part is welcome. Thesapply to both manual and automatic readings.

These remarks have been classified depending on their theme.

4.1. Correlating measured deviations to the aircraft

1. Up to now, engine modular analysis has been barely capable of aircraft performance monitoring with respect to distinguishing airfengine contributors to performance deviations. Yet, this type of analybe quite consistent with the APM analysis (DFFB parameter) intrending. Indeed, the APM / IFP (global aircraft performance) of Airthe Engine Condition Monitoring (engine performance) provided by manufacturer use consistent engine models. As a consequence,

observed with both tools should be consistent with each other.

2. A suspected airframe deterioration resulting from an observed ∆N1should be confirmed by verified (visible) aerodynamic drag / airflow dsources such as misrigging, dents, missing seals, steps, gaps, etc.

3. Therefore, conduct a visual inspection (extended walk around) of tnoting any possible aerodynamic discrepancies and possibly confirmby photographs. Also do this in flight, should a visual observation of twing surfaces be performed (slats, spoilers, flap, ailerons) and ptaken (zoom photographs).

4. For A300/A310 Aircraft asymmetry drag diagnosis can be performedZero Control Wheel technique (FCOM 2.02.09 for A310 / A300-600).

4.2. Practical aspects

1. The Specific Range (SR) method is the most effective procedure to airline practice, but crew additional considerations may pre-emp

4. As a reminder, the analysis performed with the Airbus tools i

models or databases called IFP databases or High Sp



databases. These databases are valid for cruise analysis in toperational conditions. Should not-expected conditions becruise performance analysis could be biased due to an aircraFor instance, points recorded below 20000 feet (it sometthough the systems for automatic retrieval are configured npoints), should be disregarded. However a range of altitud

should be recorded to have a spectrum of different wing loadassess the consistency of any positive or negative SR deviat

R ESULTS APPRAISAL




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F. USING THE MONITORED FUEL FACTOR



1. INTRODUCTION

Airline Flight Planning systems are based on a reference ailevel (book level or IFP level, see paragraph A-1. The book establish a fuel policy, an adjustment of this level is requireregulations (e.g. JAR-OPS) in order to get scheduled flight p

with the actual aircraft performance level.

Furthermore, airlines flight operations are usually in charge ostudies both for operational and commercial purposes. These sconducted with the Airbus high speed performance calculatsoftware allows to get aircraft performance relevant for the consequence, tuning the different fuel studies by means of t

factor is mandatory for day-to-day flight operations.

On the other hand, the FMS onboard the aircraft also performspredictions based on a reference model: the FMS performanPERF FACTOR entered in the MCDU helps to the FMS predictio

Implementing aircraft performance monitoring aims to determfuel factor. The intent of this paragraph is to correlate the facto

various fields of application on one hand with the monitored other.

In the following, the term "fuel factor" will be applied to both ma(ie the modified fuel flow is the reference fuel flow times tarithmetic deviation (in percent, ie the modified fuel flow is the rtimes the fuel factor plus 1). The same terminology will be usedwill be added to deviations in percentage.

U SING THE MONITORED FUEL FACTOR

2. FMS PERF FACTOR

2 1 Purpose



2.1. Purpose

The intent of this paragraph is to explain how to tune the FMGECpredictions using the PERF FACTOR. It mostly synthesizes the conteFlight Crew Operating Manual focusing on the FMS PERF FACTOR.Should a discrepancy be noticed between the following and the FCOMprevails.

This concerns the following FMS manufacturers:

Aircraft type Manufacturer Generic name Other

Smith-

A300-600/A310 Honeywell(Sperry)

FMS-

Honeywell FMS1 HoneywelHoneywell FMS2 Honeywel

A320 Family A330/A340

Thales FMS2 -

2.2. FMS Perf Data Base (PDB)

The main FMS aircraft performance predictions deal with:

- fuel consumption, time,- climb and descent path,- recommended maximum altitude, and- optimization of speeds and cruise altitude taking into account econom

defined by the airline Cost Index.

The PDB is derived from the IFP aircraft databases, which is consiste

book level (see also A-1. The book level ). Slight simplifications were account because of the limited size of the FMS memory. For example, oconditioning setting is available (LO/ECON as appropriate).

Th FMGEC/FMC t i i t t d i ft f d t b

U SING T



The corresponding identification is then dMCDU A/C STATUS pag

2.3. Update of the PDB

For aircraft not fitted with FMS2, the FMS PDB is part of the FMof the Perf Data Base can be done, on current FMS, only at thnew FMGEC standard certification.

For aircraft fitted with FMS2, the FMS PDB is part of the FM softsubject to a Service Bulletin and installation of a new PDB part n

2.4. PERF FACTOR definition

2.4.1. General



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Therefore, a correction should be applied when the aircraft FMnot exactly fit to the aircraft model. It results in FMS predictions aircraft book level.

2.4.3. Monitored fuel factor

On the other hand, the actual aircraft drag and engine perform

the nominal model due to the aircraft's aging process. Applyinshift the performance level from the book level to the actual enabling better fuel predictions. As a reminder, the monitored fuel factor can be obtained from performance monitoring methods.

In the absence of measurements, the monitored fuel factorassumption in terms of fuel quality. Basically, FMS predictions a

a basic FLHV equal to 18400 BTU/LB (which is very consconsequence, and in order not to over-penalize the FMS predicfuel factor should be corrected for the FLHV effect.


The arrows “1” represent the monitored fuel factor, based on a 18590 this monitored fuel factor is entered in the MCDU, the fuel predictio

consistent with LEVEL 2 (see figure F1). FMS predictions will be hence penalized. Correcting the monitored fuel factor (arrow “2”) ensures



p g ( )predictions are consistent with LEVEL 1 (see figure F1).

For example, if:1. the cruise performance analysis is performed with a FLHV equa

BTU/LB, and

2. the monitored fuel factor is equal to 2%

Keeping in mind the FMS predictions are based on a 18400-FLHV, themonitored fuel factor is equal to the monitored fuel factor corrected foreffect, that is to say:

%0.1%98.010018590

184001%0.2 ≈≈×

−−

2.4.4. FMS PERF FACTOR

The FMS PERF FACTOR must be entered in the aircraft MCDU oSTATUS page. The PERF FACTOR for the FMS predictions is the sbasic PERF FACTOR (in percent) and the monitored fuel burn depercent).

2.5. Basic FMS PERF FACTOR

On A300-600/A310 aircraft and fly-by-wire aircraft fitted with FMS1, tPERF FACTOR is defined in the hardware and is equal to 0.0.

On aircraft fitted with FMS2, the default PERF FACTOR is either 0.0 (hais defined in the FMS Airline Modifiable Information (AMI) file, also airline configuration file. The basic value defined in the AMI file correspoFor more information on that subject, read Flight Crew Operating Manua

U SING T

2.5.1. General assumptions

All these factors were determined with the following hypotheses:

Anti-Ice OFF FLHV: 18400 BTU/LB



Air conditioning:- NORM for A319, A320 (except A320 CFM fitted with F

with FMS1- LO/ECON for A320 CFM fitted with FMS2, A330, A340 w

Note: The FMS performance databases are based on a default Fuel (FLHV, see also paragraph " B-3.4.3.1.Fuel Lower Heating Valu18400 BTU/LB. So, when FLHV goes up from 18400 BTU/LB t

necessary to reset the performance factor values to –1.0%.

2.5.2. A300-600/A310 aircraft

The basic PERF FACTOR entered in the MCDU at delivery is 600/A310 aircraft.

2.5.3. A320 “CFM” engines

The “CFM” family is split into several tables due to the numeaircraft fitted with CFM56-5B engines. Indeed, this engine typhave SAC (Single Annular Combustion chamber) or DACCombustion chamber) and the “ /P” option, which is a SF

Consumption) improvement (“physically” resulting from a Hcompressor modification).

For all these aircraft the basic performance factor is given below

2.5.3.1. CFM56-5A engines

2.5.3.1.1. FMS1

Perf Factor


2.5.3.1.2. FMS2

Perf Factor

A319 113 CFM56 5A4 0 0



A319-113 CFM56-5A4 0.0

A319-114 CFM56-5A5 0.0

A320-111 CFM56-5A1 0.0

A320-211 CFM56-5A1 0.0

A320-212 CFM56-5A3 0.0

2.5.3.2. CFM56-5B engines

2.5.3.2.1. FMS1

Non /P /P

SAC DAC SAC DAC

A319-111 CFM56-5B5 0.0 0.0 -4.5 -3.5

A319-112 CFM56-5B6 0.0 0.0 -4.5 -3.5

A319-115 CFM56-5B7 0.0 0.0 -4.5 -3.5

A320-214 CFM56-5B40.0 0.0 -3.0 -2.0

A321-111 CFM56-5B1 0.0 0.0 -2.0 -1.5

A321-112 CFM56-5B2 0.0 0.0 -2.0 -1.5

A321-211 CFM56-5B3 0.0 0.0 -2.0 -1.5

A321-212 CFM56-5B1 0.0 0.0 -2.0 -1.5

A321-213 CFM56-5B2 0.0 0.0 -2.0 -1.5

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2.5.3.2.2. FMS2

Non /P /P

SAC DAC SAC



SAC DAC SAC

A319-111 CFM56-5B5 4.5 4.5 0.0

A319-112 CFM56-5B6 4.5 4.5 0.0

A319-115 CFM56-5B7 4.5 4.5 0.0

A320-214 CFM56-5B4 3.0 3.0 0.0

A321-111 CFM56-5B1 2.0 2.0 0.0

A321-112 CFM56-5B2 2.0 2.0 0.0

A321-211 CFM56-5B3 2.0 2.0 0.0

A321-212 CFM56-5B1 2.0 2.0 0.0

A321-213 CFM56-5B22.0 2.0 0.0

2.5.4. A320 “IAE” family :

2.5.4.1. FMS1

Perf Factor

A319-131 V2522-A5 –0.5

A319-132 V2524-A5 –0.5

A319-133 V2527M-A5 –0.5

A320-231 V2500-A1 0.0

A320-232 V2527-A5 +0.5

A320-233 V2527E-A5 +0.5

A321-131 V2530-A5 -0.5


2.5.4.2. FMS2

Perf Factor

A319 131 V2522 A5 0 0



A319-131 V2522-A5 0.0

A319-132 V2524-A5 0.0

A319-133 V2527M-A5 0.0

A320-231 V2500-A1 0.0

A320-232 V2527-A5 0.0

A320-233 V2527E-A5 0.0

A321-131 V2530-A5 0.0

A321-231 V2533-A5 0.0

A321-232 V2533-A5 0.0

2.5.5. A330 aircraft

2.5.5.1. FMS1

Perf Factor

A330-202 CF6-80E1A2 -1.0

A330-223 PW4168A -1.0

A330-243 TRENT772B-60 -3.0

A330-301 CF6-80E1A2 0.0

A330-321 PW4164 0.0

A330-322 PW4168 0.0

A330-323 PW4168A 0.0

A330-341 TRENT768-60 0.0

A330 342 TRENT772 60 OH (*1) 0 0




2.5.6.2. FMS2

Perf Factor

A340-211 CFM56-5C2 -2.0



A340-212 CFM56-5C3 -2.5

A340-213 CFM56-5C4 -1.0

A340-213E CFM56-5C4 0.0

A340-311 CFM56-5C2 0.0

A340-312 CFM56-5C3 -1.0

A340-313 CFM56-5C4 0.0

A340-313E CFM56-5C4 0.0

A340-642 TRENT 556 + 0.5 %

2.6. Procedure to change the PERF FACTOR

The PERF FACTOR should be regularly updated based on the routiperformance monitoring. This paragraph details the procedure to cPERF FACTOR in the CDU/MCDU.

Airbus recommends that only authorized and qualified staff members pprocedure. The crew should not change the value by themselves.

The PERF FACTOR can only be modified on ground.

Note: On fly-by-wire aircraft, the PERF FACTOR is displayed in CYAN when(modifiable) and in GREEN when airborne or when no change code was modifiable). It is displayed in large blue font, following a modification.

U SING T



2.6.1. A300-600/A310 aircraft

1. Select the CDU A/C STATUS page2. Type the new value3. Press LSK 6L.

2.6.2. A320 Family aircraft

2.6.2.1. Aircraft fitted with FMS1


Following steps describe how to change the PERF FACTOR value:1. Enter“ ARM”in the CHG CODE line [5L ]brackets (or appropriate p

2. Write the new IDLE/PERF factor in the scratchpad3. Enter this new factor in line [6L ]. The entered factor is displayed in la

font.



font.

The airline may change the ARM code by modifying the NAV DATA BASfile.

2.6.3. A330/A340 aircraft

On the MCDU A/C STATUS page:

1. Enter ARM into brackets in the CHG CODE line [5L ]2. Write the new IDLE/PERF factors3. Insert the new factor using [6L] key. A manually entered IDLE/PER

displayed in large CYAN fonts.

2.7. Effects of the PERF FACTOR

Adjusting the PERF FACTOR has an impact on fuel flow predictionconsequence, comparing the scheduled fuel consumption with or witho

a PERF FACTOR will exhibit noticeable differences. The purposparagraph is to succinctly describe the influence of the PERF FACTOR.

First, PERF FACTOR is an FMS internal correction. It is not sent to computer linked to the FMS (FADEC, EIU…).

Second, as defined above, the PERF FACTOR basically modifiespredicted fuel flow. Hence, it impacts the items listed below.

2.7.1. Estimated fuel on board (EFOB) and estimated landing we

U SING T

2.7.2. ECON speed/Mach number

The ECON speeds are calculated so as to minimize the cost

function depends on the predicted fuel flow or predicted specCost Index entered in the MCDU and on the ground speed.



The PERF FACTOR therefore has an influence on the predictThe Cost Index used for ECON speeds computation is modifiefollowing formula:

1001

FACTOR PERF CI CI PF

+=

where CI is the Cost Index entered in the MCDUCIPF is the corrected Cost Index for the PERF FACTOPERF FACTOR is the factor entered in the MCDU

Yet, the influence of the PERF FACTOR is quite small. The highgenerally observed at high gross weights. The effect is m A330/A340 aircraft types.

As a general rule, the higher the PERF FACTOR, the lower the E

2.7.3. Characteristic speeds

The FMS computes flight characteristic speeds and displays thin the MCDU PERF pages. As a reminder, the characteristic spO speeds during the T/O and APPR phases, VLS and VAPP CFULL during the APPR phase.

The characteristic speeds are calculated based on the predicweight, which is the sum of the zero fuel weight (ZFW) and theboard (EFOB).

A h PERF FACTOR difi h EFOB i l i h


- flown in level flight without acceleration with an engine rating lesscruise,

- reached before buffeting (the margin depends on the aircraft mode

fly-by-wire aircraft)

It is displayed on the MCDU PROG page.



p y p g

The REC MAX ALT is less than or equal to the CERtified MAXimum Aprovided in the Airplane Flight Manual (AFM). This calculation is peupdated during flight.

The REC MAX ALT is a pre-computed value function of the aircraft groand the ISA deviation (the ISA model is defined in the FMGEC tha

temperature and the tropopause altitude that are entered in the MCDU).

As a consequence, the PERF FACTOR has no influence on the REC MA

U SING T

It is displayed on the MCDU PROG page.



The calculation is made taking into account: the Cost Index,weight (GW), the wind model, the temperature model (Inter Atmosphere) and the ISA deviation.

Since the PERF FACTOR modifies the fuel flow, it changes the consequence, the OPT ALT is also impacted.

A positive PERF FACTOR decreases the OPT ALT, all othefixed.

3. FUEL FACTOR FOR FLIGHT PLANNING S YSTEMS

During the dispatch of any aircraft, each operator must determinthat is required for a safe trip along the scheduled route, and


The intent of the following lines is to clarify Airbus recommendations in tefactor for flight planning preparation.

3.1. Effect of the fuel factor on Flight Planning



The following picture illustrates the different fuel quantities and assocphases of a typical trip.

The fuel factor defined in flight planning will modify (except fixed values o- the trip fuel- the contingency fuel (generally a percentage of the trip fuel)- the alternate fuel- the final reserve (holding at alternate fuel)- the additional fuel

3.2. Keys for defining the fuel factor

U SING T

The following points must be emphasized:

1. When determining an operational flight plan at fixed speed

manual mode), the flight planning fuel factor must be the measured with an appropriate aircraft performance monitorinwords, the fuel factor for flight planning is equal to the monito



2. When determining a flight plan (or a part of it) at Cost Index E

• the ECON speeds must be calculated taking into accouFACTOR

• the flight plan must be calculated with the pre-calculateusing a method consistent with the standard IFP algorithaccount the monitored fuel factor.

Note: Read paragraph 4. Airbus Tools and Fuel Factor to have mo

capabilities of the Airbus tools covering that subject.

3. The Fuel Lower Heating Value is included within airline infoto Flight Planning. The FLHV should be the same as thecruise performance analysis. If not, a correction will bmonitored fuel factor.If the FLHV for cruise performance analysis is 1% higher thin the flight planning system, decrease the monitored fuel fac

For example, if :

1. the cruise performance analysis is performed with a FLHBTU/LB, and

2. the flight planning is calculated based on a FLHV equal and

3. the monitored fuel factor is equal to 2% Assuming no Cost Index calculation is done, the flight planequal to the monitored fuel factor corrected for the FLHV effe

%0.1%98.010018590184001%0.2 ≈≈× −−

4 The FMS PERF FACTOR should be indicated on the comp


3.3. Comparing FMS fuel predictions and ComputerizePlanning

FMS fuel predictions and scheduled fuelplanning indeed have different purposes. Yet,



planning indeed have different purposes. Yet,it is tempting to try to compare both fuelschedules. The intent of the following is toremind the main reasons for thesedifferences.

As explained in this chapter, the FMSpredictions are based on an FMS simplifiedperformance database, which is differentfrom the CFP aircraft database (consistentwith the book level).

1. The fuel factors defined in the FMS(PERF FACTOR) and those destinated for flight planning computation (flight planningfuel factor) must be consistent with eachother.

2. The FMS predictions may be calculatedwith different wind predictions than the

Computerized Flight Planning (windprofile). The influence of the wind onperformance is tantamont.

3. The flight planning computation method can induce hidden effects: Some flight plannings are based on Flight Crew Operating M

calculated data. The flight plan is then calculated interpolating witdata.

Some flight planning systems are based on pre-calculated data Airbus IFP program. The flight plan is then calculated interpolaresulting data tablesS th fli ht l i t b d

Figure F1 - Example of compu

U SING T

Example of difference between CFP and FMS predictionsFigure F2 shows an example of predictions, for the same route,

conditions being fulfilled.



Figure F2 - Comparison CFP versus FMS predictions

Apart from the routing errors, the figures in both cases are queach other.

4. AIRBUS TOOLS AND FUEL FACTOR

All airline Flight Operations use or at least have heard abouSpeed Performance calculation software. The intent of this parexplain how to use fuel factors with these tools.

The Airbus HSP software is composed of:- the IFP program- the FLIP program


4.1. The IFP program

This paragraph describes the way to use fuel factors (monitored fuel faPERF FACTOR) in the IFP program, depending on what is needed.details on the IFP functions, read 0-1.1.3. The IFP program.



4.1.1. The IFP calculation modes

The IFP has three basic calculation modes. They are described down be

4.1.1.1. Standard mode

Calculations performed with this mode are based on the most accuratmodel of the aircraft available (so-called the IFP model or book level), most accurate fuel predictions for given speeds. Calculations are peconomic speeds for the cruise phase only, by selecting the "optimuoption. But, the resulting calculations will not match up entirely with the saircraft will be adopt by means of the FMS and in equivalent conditions. indeed based on the optimization of the cost function using slightly diffthan those stored in the FMS.

This calculation mode is based on:- Standard IFP aerodynamic and engine database (same as book leve- Standard IFP algorithms for data extraction and flight mechanics equ- Standard data and algorithms for flight guidance parameters and limi

- Adjustable atmospheric conditions- All air conditioning settings available- All anti ice settings available- Adjustable FLHV- Adjustable drag factor (modification of the aircraft drag)- Adjustable fuel consumption factor (modification of the fuel flow)

4.1.1.2. FMS modeCalculations performed with this mode are based on the databases stoFMS (FMS Perf Data Base or PDB) on the simplified equations used tht th l ti t i t ) F i t i d d f l f t

U SING T

This calculation mode is based on:- Simplified IFP aerodynamic and engine database (FMS ai

level),

- Simplified IFP algorithms for data extraction and flight meconsistent with the ones implemented in the FMS,

- Data and algorithms for flight guidance parameters and limwith the FMS ones



with the FMS ones- Adjustable atmospheric conditions- LO/ECON air conditioning only, no anti-ice, as the FMS pred- Adjustable FLHV- Adjustable drag factor

- Adjustable fuel consumption factor

4.1.1.3. hybrid mode (standard with FMS speeds)

This mode uses a mix of the two previous database sets in ordeof both worlds: the actual FMS speeds and accurate fuel consuunder given conditions. For example, you may calculate data fo

available on the aircraft. For the flight phases being covered, thiflight plan performance data production. The ones not covered aFMS selected or manual mode (single engine performance, gFMS managed mode is equivalent to a calculation in standardgreen dot speed...).

This calculation mode is based on:- Standard IFP aerodynamic and engine database (same as b

- Standard IFP algorithms for data extraction and flight mecha- Data and algorithms for flight guidance parameters and lim

with the FMS ones- Adjustable atmospheric conditions- All air conditioning settings available- All anti ice settings available- Adjustable FLHV

- Adjustable drag factor - Adjustable fuel consumption factor


4.1.2.2. Flight at given speed (CAS/Mach)

This type of calculation is only possible for the CRZ and DES phases. calculations can be performed for the CLB phase as the IFP FMS calc

climb Mach depending on the Cost Index entered.

The IFP FMS mode should be used with the following assumptions:1 FLHV set equal to 18400 BTU/LB (as in the on-board FMS)



1. FLHV set equal to 18400. BTU/LB (as in the on-board FMS)2. LO/ECON air conditioning3. Fuel Consumption Factor set equal to (1+FMS PERF FACTOR(%)/104. Drag factor set equal to 1.05. Atmospheric conditions as close as possible to the ones used by the 6. Speeds as applicable

4.1.3. Determination of the actual aircraft performance

The intent of this paragraph is to explain how to use the IFP program toactual aircraft performance.

4.1.3.1. Flight at given Cost Index

Airbus recommendation is to use the HYBRID mode.

The HYBRID mode will perform the ECON speeds and fuel flow calculafuel factor(s) have an influence on both types of items. The point idifferent fuel factor(s) must be used:- FMS PERF FACTOR to obtain ECON speeds- Monitored fuel factor to obtain fuel flows

In the IFP, only one consumption factor can be entered. The following girecommendations to bypass that constraint.The FLHV is used during the calculation of fuel flows. Basically, the FLHV, the lower the fuel flow. The whole idea is to modify the FLHV byamount in order to compensate for the difference between the F

FACTOR and the monitored fuel factor, that is to say, to compensateFMS PERF FACTOR.

As a general assumption one percent FLHV deviation results in on

U SING T

Then,

A ACTUALCORR FLHV FLHV FACTOR PERF FMSFLHV +×∆= (%) _ _

The IFP HYBRID mode should be used with the following assum1. Corrected FLHV (see above)2 Air conditioning/Anti Ice as appropriate



2. Air conditioning/Anti Ice as appropriate3. Fuel Consumption Factor set equal to (1+FMS PERF FACTO4. Drag factor set equal to 1.05. Atmospheric conditions as close as possible to the actual one

6. Cost Index as applicable


The IFP STANDARD mode should be used with the following as1. FLHV as appropriate2. Air conditioning/Anti ice as appropriate3. Fuel Consumption Factor set equal to monitored fuel factor

4. Drag factor set equal to 1.05. Atmospheric conditions as close as possible to the actual one6. Speeds as applicable

4.2. The FLIP program

This paragraph describes the way to use the FLIP program witfactors, depending on the objective.

4.2.1. The FLIP missions

4.2.1.1. Standard Flight Planning

Calculations performed with this mode are based on the mostmodel of the aircraft available (so-called the IFP model), giving fuel predictions for given speeds.


4.2.1.2. FMS Flight Planning

Calculations performed with this mode are based on the databases stoFMS (FMS Perf Data Base or PDB) and on simplified equations used th

to the real-time constraints).

For a given cost index and fuel factor, speeds given in this mode arsame as those flown by the aircraft in identical conditions. The fuel co



ymay be slightly different from the ones actually observed, since theresimplifications, like the assumption of low air conditioning and no anti icethe actual bleed flow. Another restriction: only flight conditions that caunder FMS managed mode by the crew are available for computation.

This calculation mode is based on:- Simplified IFP aerodynamic and engine database (FMS aircraft pe

level)- Simplified IFP algorithms for data extraction and flight mechanics

consistent with the ones implemented in the FMS- Data and algorithms for flight guidance parameters and limitations

with the FMS ones- Adjustable atmospheric conditions- LO/ECON air conditioning only, no anti-ice, as the FMS predictions- Adjustable FLHV- Adjustable thrust factor - Adjustable fuel consumption factor

4.2.1.3. Standard Flight Planning with FMS speedsThis mode uses a mix of the two previous database sets in order to obtaof both worlds: the actual FMS speeds and accurate fuel consumption punder given conditions. For example, you may calculate data for any bleavailable on the aircraft. The FMS managed mode is equivalent to a calstandard mode.

This calculation mode is based on:- Standard IFP aerodynamic and engine database (same as book leve- Standard IFP algorithms for data extraction and flight mechanics equ- Data and algorithms for flight guidance parameters and limitations




The FLHV is used during the calculation of fuel flows. Basically spehigher the FLHV, the lower the fuel flow. The point is to modify the Fcertain amount in order to compensate for the difference between the F

FACTOR and the monitored fuel factor, that is to say, to compensateFMS PERF FACTOR.

As a general assumption, one percent FLHV deviation results in ond i ti i f l fl Th



deviation in fuel flow. Then,

(%) _ _ FACTOR PERF FMSFLHV

FLHV FLHV

ACTUAL

ACTUALCORR ∆=−

where FLHV ACTUAL is the actual FLHVFLHVCORR is the corrected FLHV

∆FMS_PERF_FACTOR(%) is the basic FMS PERF FACTOR

Then,

ACTUAL ACTUALCORR FLHV FLHV FACTOR PERF FMSFLHV +×∆= (%) _ _

The Standard Flight Planning with FMS speeds mission should be usefollowing assumptions:1. Use ECON speeds (managed mode)2. Corrected FLHV (see above)3. air conditioning/anti ice as appropriate

4. Fuel Consumption Factor set equal to (1+FMS PERF FACTOR(%)/105. Thrust factor set equal to 1.06. Atmospheric conditions as close as possible to the actual ones7. Cost Index as applicable


The Standard Flight Planning mission should be used with theassumptions:1. FLHV as appropriate2. Air Conditioning/Anti Ice as appropriate

P OLICY FOR

G. POLICY FOR UPDATING THE FUEL FAC

1. INTRODUCTION

When implementing routine aircraft performance monitoring one



p g p gdefine some indicators and trigger conditions that may help dactually change the aircraft fuel factors. The intent of this pa Airbus recommendations to the operators updating of the F

factor and the FMS PERF FACTOR. It is the operator's responsthis update procedure within its company fuel policy.

The previous paragraphs made an exhaustive review of the difthese indicators into place: monitored fuel factor, monitored deltThis chapter focuses on the main items that must be taken illustrates this with examples coming from the field.

The following is based on Airbus experience as well as on feedbsome operators.

2. STARTING OPERATIONS WITH A NEW AIRCRAFT

At delivery of a new aircraft, no data is available for this tail nuthe required fuel factors to adjust the computerized flight plapredictions. At delivery, it is common practice to perform a sample points to establish fuel factors.

With these few points, an FMS PERF FACTOR and a flight plandetermined in accordance with chapter F-Using the monitoreFMS and flight planning system are adjusted with these factors.

Later on, fuel factors are adjusted for each individual aircraft byperformance monitoring. At the very beginning of the operatcross check may be performed with another method to assess

P OLICY FOR UPDATING THE F UEL F ACTOR

3. A PERF FACTOR FOR EACH AIRCRAFT?

For the sake of simplification, it may be tempting to try and determine fuapplicable to all tail numbers. Indeed, doing so will avoid multiple calculaspecific aircraft and would allow to use the same flight planning basic ifor the whole fleet.Yet this will certainly penalize most of the fleet Indeed the different



Yet, this will certainly penalize most of the fleet. Indeed, the different airline are not delivered at the same date. The different aircraft may beon different routes, accumulating different cycles and flight homaintenance done on the aircraft may also result in different consequ

cruise performance analysis (engine change on a specific aircraft will change the monitored fuel factor for the concerned aircraft). To sumindividual aircraft has its own history.

Airlines usually tailor the performance factor to each individual aircrafthe cruise performance analysis at the tail number level allows to adjuslevel to the actual aircraft performance of each tail number. Thus, for a

number, the computerized flight planning, the FMS predictions and any rwill be customized to each individual aircraft.

It is worth mentioning that the other advantage of routine performance is that analysis result may evidence unusual conditions by comparingnumber to the rest of the fleet. Thus, this procedure may also contconditions for warning the airline maintenance department, in order toaircraft as good as possible.

4. CHANGING THE FUEL FACTOR

4.1. Introduction

Changing the fuel factors is defined in each airline fuel policy. It may depending on the airline structure and means available for flight planningoperations. The following will show some examples, which cannot bplace "as is" b t sho ld an a be adapted to each indi id al airline’s n

P OLICY FOR

Whatever the airline policy, some techniques are usually used toof the fuel factor evolution versus time.

4.2. Some precautions

The following illustrates the way to change the fuel factors throThe result of cruise performance analysis gives the fuel facto



time. Figure G1 shows an example of monitored fuel factor versu

1

2

3

4

Sep-01 Oct-01 Nov-01 Dec-01 Jan-02 Feb-02 Mar-02 Apr-02 May-02

Month

M o n i t o r e

d F u e l F a c t o r ( % )

Figure G1 - Example of Monitored Fuel Factor degradation with t

4.2.1. Monitored fuel factor trend line

The monitored fuel factor is established with a certain accuracexplained at the beginning of this brochure. The determinastatistical one. For each month, the monitored fuel factor displayThis induces that the trend of the fuel factor is not purely monitored fuel factor can decrease from one month to anothsense may make one wonder how aircraft performance can incre

P OLICY FOR UPDATING THE F UEL F ACTOR

4.2.2. Update frequency

Figure G1 shows something interesting about the evolution of the mea

factor. Indeed, over 6 months, the monitored fuel factor went up by 0.5%

As of a consequence, checking the evolution of the monitored fueuseless when it is performed too often. Most of the airlines check fuel faa month which ensures noticeable and acceptable variations



a month, which ensures noticeable and acceptable variations.

This rule applies for fuel factors determination. Aircraft performance with the APM program may also be used to monitor the aircraft a

condition. In that case, the frequency must be adapted in order not to svariations of the different and to hide some indicators.

4.2.3. Two examples of trigger condition for updating the fuel fac

The two examples explained below illustrate the way the decision to cfuel factor is made in two different airlines. This procedure depends on t

of conservatism the airline is ready to add to fuel fact determination factor.

Indeed, changing fuel factors too early will increase predicted aconsumption on computerized flight planning, leading to possibly carrythan required. Airbus has not yet performed any check concerning thimpact and is ready to discuss this item with any airline interested in thYet, the uncertainty on the monitored fuel factor is such that this does

the operations in a large extent.

4.2.3.1. Example 1: Step Fuel Factors

The principle of this method is to retain approximate values for monfactors. The fuel factor is changed when a difference of more thapercentage is noticed between the new figure and the last one retaine

words, this technique allows a certain margin or error in the determinafuel factor.

Figure G2 on next page shows the actual monitored fuel factor as meas

P OLICY FOR

2.42.5

2.72.8

2.9

2.6

2.8

2.5

3

3.5

F u e l F a c t o r ( % )



1

1.5

2

Sep-01 Oct-01 Nov-01 Dec-01 Jan-02 Feb-02 Mar-02 Ap

Month

M o n i t o r e d

Actual Monitored Fuel Factor Retained Monitored Fuel F

Figure G2 - Step Fuel Factor method

This example assumes a minimum delta of 0.5% is the conditiothe fuel factor.

In October 2001, the monitored fuel factor was set to 2.5 %. A(FMS PERF FACTOR, Flight Planning fuel factor…) were upaccount this new value.

In the following months, until March 2002, the monitored fueevaluated monthly to be compared to the previous one retainethe monitored fuel factors got above 2.5% + 0.5% = 3.0%, sperformed. In April 2002, the monitored fuel factor got equal to 3fuel factor became 3.0% instead of 2.5%, because the margin wIn May 2002, the monitored fuel factor got below 3.0% again. Nto avoid ups and downs (which cannot be avoided around the ste

Definitely the advantage of this method is that it is a simplecontrollable. The only point is to define the margin. In comdetermination of the fuel factor is scattered and biased One



P OLICY FOR

Of course, this smoothing technique is a quite simple (but efficcould imagine developing a specific smoothing technique basethe like. Airbus is prepared to share its view with any airline inte

sake of airline operations improvement.

5. WHO CHANGES THE FUEL FACTOR(S)?



The intent of this paragraph is to give the Airbus view on who ma change of fuel factor on one hand, and who should have the adoes not impose any way of working neither aim to substit

practice.

Airline Flight Operations staff members should define the diffebased on an aircraft performance monitoring method. Foperformance monitoring, the Specific Range method and theprogram will facilitate recurrent analysis.

Note: The AMM does not provide any procedure to change this factor.

Airline Flight Operations will trigger a change in fuel factor(srelevant figures to supervisory management and to operational t- in charge of the flight planning system update (Flight Plannin- in charge of updating of the FMS PERF FACTOR on

(Maintenance, Avionics…)

P OLICY FOR UPDATING THE F UELF ACTOR




H. APPENDICES

This chapter gathers additional material dealing with aircmonitoring.

Appendix 1 : High Speed Performance Software



Appendix 2 - Fuel-Used method

Appendix 3 - Trip fuel burn-off method

Appendix 4 - Airbus Service Information Letter 21-091

Appendix 5 – AMM extracts

Appendix 6 – Auditing aircraft performance in airline revenu

APPENDICES

1. APPENDIX 1 : HIGH SPEED PERFORMANCE SOFTWARE

1.1. P.E.P for Windows

1.1.1. What is P.E.P. ?

The PEP for Windows working environment aims at providing the neces



The PEP for Windows working environment aims at providing the necesto handle the performance aspects of flight preparation, but also to monperformance after flight. It is dedicated to airlines’ Flight operations a

offices. Based on the Microsoft Windows © operating system, theWindows is a stand-alone application, which offers access to all the Airbperformance computation programs in a user friendly and cusenvironment. In addition to an easy-to-use setup tool, useful tools like tManager”, the “Batch manager” and the “On-line Help” have been implem

1.1.1.1. Objectives

In order to better understand the main objectives of the PEP for Windowenvironment we first need to recall that the previous working environbased on the DOS operating system. Each performance calculation probeen developed separately from the others.This is why the main objectives of this working environment are :- To provide a working environment using the Microsoft Windows ©

system for all Airbus performance computation programs.- To harmonize layout and behavior of all program interfaces.

- To improve user-friendliness of these user interfaces.

- To develop and introduce new tools in order to ease the hanmanagement of data.

- To improve access to Performance Programs documentation bythanks to an On-line Help.

Some of these objectives have been achieved through one of the PEP

(16-bit for transition) and others through the PEP version 2 (32-bit).

1 1 1 2 Scope

1.1.2. Performance Computation Programs

The PEP for Windows platform provides access to the followPerformance Programs :

FM program: It is the computerized Flight Manual andprogram for A300-600, A310 and A320 (certified for Acertified part of the OCTOPUS program for A319



certified part of the OCTOPUS program for A319, A340.

TLO program: It allows takeoff and landing opti“Takeoff Charts” and it consists of TLC (or TCP prog A310 and A320 and the former optimization part program for A319, A321, A330 and A340.

IFP program: It provides aircraft performance for “phases such as climb, cruise, descent, … andconsultation tool of aerodynamic and engine data. It Airbus aircraft types.

OFP program: It is devoted to determining the airengine operating) and various configuration paramdefined flight path at takeoff or in approach (i.e. Lowalso computes trajectories (with cutbacks for examp

determination, which then becomes an input for the applicable for all Airbus aircraft types (but with podelays for some of them).

APM program: It allows the user to compare and aircraft In-flight performance level versus the theoalong the aircraft life for all Airbus aircraft types.

FLIP program: It is a Flight planning software, whi

APPENDICES

1.1.3. The IFP program

The In Flight Performance program is the first program

speed performance calculation within the PEP package.This tool is an engineering oriented tool and as such it is within the frame of specific studies and various crequired by the day-to-day work of an operation engineer



The main tasks in which the IFP program can assist the engineer are:

- Computation of instantaneous or integrated performance data for a fl

- Simulation of FMS computation- Extraction of aerodynamic characteristics and engine performance d

aircraft model

1.1.4. The APM program

For years, the business environment has been becoming more challenging. Yields are dropping while competition is iBusiness traffic is volatile, aircraft operations are becomingmore expensive and the price of spare parts are escalating faster. Airlines have to face with new objectives to adaenvironment.

Fuel burn makes up for ten percent of the direct operating cost

maintenance makes up for another quarter. The operator's main ctherefore to have high quality information about the condition and the peof the aircraft whenever needed.

That’s why Airbus feels deeply involved in aircraft performance monitora consequence has been proposing for years some tools for aircraft pemonitoring as well as some guidelines for performing aircraft performanc

Airbus has developed one tool within its aircraftperformance software devoted to cruiseperformance analysis: the Airbus Aircraft

Commercial flight planning providers like Jeppesen, SITA oraccurate routing information taking into account actual weaththese systems work with pre-calculated aircraft performance dat

For some critical routes, this level of precision may not be high ea financially sound operation. This is why Airbus provides operator to validate the fuel burn predicted by such commercial own software, the FLIP.



1.2. SCAP Programs and Unix Versions

Airbus Flight Operations Support & Line Assisregularly participates to the IATA SCAP (Stand Aircraft Performance) meetings with other manufacrepresentative.

In accordance with the “Standard definition” agreed

to these meetings, Airbus provides Airlines Fligh“SCAP compliant” computation programs written in F

These calculation programs are called “SCAP programs”. Suoperator, has to write its own calling program, which defines eaccalls the calculation sub-routine and recovers the output parame

The available “SCAP Programs” are:

- SCAP TAKEOFF (OCTOPUS-SCAP-TAKEOFF or AT

performance optimization),- SCAP LANDING (OCTOPUS-SCAP-LANDING or AL

performance optimization),- SCAP CLIMB-OUT (for takeoff or approach trajectories comp- SCAP IFP (for in-flight performance computation),- SCAP APM (for aircraft performance monitoring).

The SCAP programs are not embodied in the PEP for Windowsare available upon request from operators receiving the PEP for



2.2. Measurement procedures and precautions

The next page figure shows a sample recording form for handwr

2.2.1. Prior to take-off

- Calculate fuel on board at MES by taking remaining f(measured at truck) accounting for actual fuel density.Determine ZFW and take off CG



- Determine ZFW and take-off CG- Note APU running time since MES- Compute APU fuel consumption to amend FU



2.2.2. In flight

• Verify aircraft to be flying level in cruise for at least 40 minutes

• Perform fuel balancing if tank balance exists

• Establish nominal aircraft configuration for the cruise segment wwill be taken, i.e. :

- Autothrottle: ONAutopilot: As required e g ALT HLD / HDG / NAV



- Autopilot: As required e.g. ALT HLD / HDG / NAVor ALT HLD / NAVor PROF / NAV

- Air conditioning: NORM- Anti-icing: OFF- Trimming: ZCW on A310 / A300-600

• Whenever possible, the analysis will be conducted on selected dthe following stability criteria:

∆Zp < 50 feet/ 30 minutes

∆SAT < 5°C / 30 minutes

∆GS < 10 kts / 30 minutes∆TAS < 10 kts / 30 minutes

• Note the accurate values of fuel used engine 1 & 2 (FU1 & FU2) a

• Record data for at least 30 minutes, if conditions permit, from staminutes until the end, using adjacent fuel-used recording form:

- UTC, latitude or station - Track / course

- CG, - Wind speed / direction- FU1 / FU2 - Heading and drift- Total fuel on board (FQI) - TAS / Ground Speed- altitude (Zp) – (channel 1 and 2) - N11 / N12 (EPR1 / EPR2) - Mach – (channel 1 and 2) - FF1 / FF2 (engine 1 & 2)- SAT / TAT

• Note the accurate values of fuel used engine 1 & 2 (FU1 & FU2) at

• Note also latitude or station approaching, drift, heading, wind velo/ course for calculation of effects mentioned in section 3.

• Do not forget to consult weather charts (forecasts and actual) tt

APPENDICES

−−−− Average TAT/SAT

−−−− Fuel used = (fuel used at end – fuel used at start) or (FQI start – FQI end)

−−−− Aircraft CG (based on takeoff CG and fuel burn schedule (if not mentioned)

The IFP is then used to compute the predicted fuel used for the aircraft flaverage recorded flight conditions, over a time span equal to ∆t and starting equal to GW start. The ratio of measured and predicted fuel used will provide performance relative to the published model. The following schematic procedure flow:



2.3.1. Notes

1) Selection of several 40-minutes samples from the recorded data allows a to be obtained and measurement scatter to be evaluated, which is indicatstability and smoothness.

2) The improved FU method (whose principle is explained in paragraph 2refined results and allows very precise measurements.




APPENDICES




3. APPENDIX 3 - TRIP FUEL BURN-OFF METHOD

This method compounds genuine performance (engine/airaccuracy) with apparent performance deviations caused by difthe actual flight profile (and conditions) and the IFP – predictedconditions) such as:

- Wind and SAT profile predictions,Flight profile (Climb profile Top of Climb Cruise Mach St



- Flight profile (Climb profile, Top of Climb, Cruise Mach, StDescent, Descent profile, Holding) predictions.

- Fuel burn-off predictions (model, performance factor, LHV)- Operational factors (e.g. center of gravity position, air c

aircraft weight, aircraft trimming).- Environmental factors (e.g. coriolis-Effect, local gravity,

isobaric slopes caused by pressure and temperature gradien

As in the FU-method all flight parameters are averaged over allow a numeric approximation per flight phase prior to input

recalculation.

APPENDICES



4. APPENDIX 4 - AIRBUS SERVICE INFORMATION LE



APPENDICES



5. APPENDIX 5 - AMM EXTRACTS - CRUISE PREPORT <02> DESCRIPTION EXAMPLE

The following pages show an example of technical description focruise performance report. The following was extracted from a an A320 aircraft fitted with an IAE engine.

As a reminder, this file may be used as the primary source



routine performance monitoring.

+--------------------------------------------------------- |Code|Item | |Prog | No.|No. | Description of Function Item |MCD | | | |GSE |----|------|-----------------------------------------|--- |--------------------------------------------------------- | AI = Programmable by Airbus Industrie | C = Programmable by Customer +---------------------------------------------------------

L. Cruise Performance Report <02>(R f Fi 012)



(Ref. Fig. 012)

The cruise performance report is a collection of aircra information averaged over a period of time in which bot the aircraft met the appropriate stability criteria. Th performance report is generated when one of the logic co 5000 (for details see cruise performance report logic)

(1) Cruise Performance Report Data Field Description (E

+------------------------------------------------------

| Value | Content Description |--------------|--------------------------------------- | TAT/ALT/CAS/| In the report line CE is the averang | MN/GW/CG | F02 * 20 sec. of System 1 parameters | | | | In the report line CN is the averang | | F02 * 20 sec. of System 2 parameters |--------------|--------------------------------------- | ESN | Engine Serial Number

| 999999 | (000000 to 999999) | | Eng 1 param. 7C.1.046.01 digit 3, 2, | | 7C.1.047.01 digit 6, 5, | | Eng 2 param. 7C.2.046.01 digit 3, 2, | | 7C.2.047.01 digit 6, 5, |--------------|--------------------------------------- | EHRS | Engine Flight Hours | 99999 | (00000 to 99999 hours) | | DMU Engine 1 and Engine 2

|--------------|--------------------------------------- | ECYC | Engine Cycle | 99999 | (00000 to 99999)

|--------------|---------------------------------------



+------------------------------------------------------ | Value | Content Description |--------------|--------------------------------------- | | XX Auto Pilot Modes: | | || | | ||__Lateral Modes: 0 = NO MODE | | | 1 = HEADING | | | 2 = TRACK | | | 3 = NAV | | | 4 = LOC CAPTURE | | | 5 = LOC TRACK

| | | 6 = LAND TRACK



| | | 6 = LAND TRACK | | | 7 = RUNWAY | | | 8 = ROLL GO AROUN | | | | | |__Longitudinal Modes: 0 = NO MODE | | 1 = PITCH G/A | | 2 = PITCH T/O | | 3 = G/S TRACK | | 4 = G/S CAPTU | | 5 = V/S

| | 6 = FPA | | 7 = ALT | | 8 = ALT ACQ | | 9 = OPEN CLB | | A = OPEN DES | | B = IM CLB | | C = IM DES | | D = CLB | | E = DES

| | F = FINAL DES | | G = EXPEDITE | | | | AP1 | AP2 | | Report Line EC: | Report Line EE: | | -------------------|------------------ | | / | / | | -------------------|------------------ | | 01.1.275.00.11 = 1 | 01.2.275.00.11 =

| | -------------------|------------------ | | 01.1.275.00.12 = 1 | 01.2.275.00.12 = | | -------------------|------------------

| | 01 1 275 00 13 = 1 | 01 2 275 00 13 =

+------------------------------------------------------ | Value | Content Description |--------------|--------------------------------------- | | -------------------|------------------ | | 01.1.275.00.15 = 1 | 01.2.275.00.15 = | | | | | -------------------|------------------ | | 01.1.275.00.16 = 1 | 01.2.275.00.16 = | | -------------------|------------------ | | 01.1.275.00.17 = 1 | 01.2.275.00.17 = | | -------------------|------------------

| | 01.1.274.00.15 = 1 | 01.2.274.00.15 =



| | 01.1.274.00.15 1 | 01.2.274.00.15 | | -------------------|------------------ | | 01.1.274.00.16 = 1 | 01.2.274.00.16 = | | -------------------|------------------ | | 01.1.274.00.17 = 1 | 01.2.274.00.17 = | | -------------------|------------------ | | 01.1.274.00.18 = 1 | 01.2.274.00.18 = | | -------------------|------------------ | | 01.1.274.00.19 = 1 | 01.2.274.00.19 = | | AND | AND

| | 01.1.274.00.20 = 1 | 01.2.274.00.20 = | | -------------------|------------------ | | 01.1.274.00.19 = 1 | 01.2.274.00.19 = | | AND | AND | | 01.1.274.00.21 = 1 | 01.2.274.00.21 = | | -------------------|------------------ | | 01.1.274.00.20 = 1 | 01.2.274.00.20 = | | AND | AND | | 01.1.274.00.22 = 1 | 01.2.274.00.22 =

| | -------------------|------------------ | | 01.1.274.00.21 = 1 | 01.2.274.00.21 = | | AND | AND | | 01.1.274.00.22 = 1 | 01.2.274.00.22 = | | -------------------|------------------ | | 01.1.274.00.23 = 1 | 01.2.274.00.23 = | | | | | -------------------|------------------ | | 01.2.274.00.24 = 1 | 01.2.274.00.24 =

| | -------------------|------------------ | | 01.1.146.00.14 = 1 | 01.2.146.00.14 = | | |

| | -------------------|------------------



+------------------------------------------------------ | Value | Content Description |--------------|--------------------------------------- | 9999 | (0.6 to 1.8) | | Eng 1 param. 7C.1.341.01 | | Eng 2 param. 7C.2.341.10 |--------------|--------------------------------------- | EGT | Selected T495 (Exhaust Gas Temperatu | X999 | (-80 to 999.9 C) | | Eng 1 param. 7C.1.345.01 | | Eng 2 param. 7C.2.345.10 |--------------|---------------------------------------



| N1 | Selected N1 Actual | 9999 | (0 to 120.0 %rpm) | | Eng 1 param. 7C.1.346.01 | | Eng 2 param. 7C.2.346.10 |--------------|--------------------------------------- | N2 | Selected N2 Actual | 9999 | (0 to 120.0 %rpm) | | Eng 1 param. 7C.1.344.01 | | Eng 2 param. 7C.2.344.10 |--------------|--------------------------------------- | FF | Engine Fuel Flow | 9999 | ( 0 to 8500 kg/h) | | Eng 1 param. 7C.1.244.01 | | Eng 2 param. 7C.2.244.10 |--------------|--------------------------------------- | P125 | PS125 Static Air Pressure at Positio | 99999 | (0.0 to 30.000 psia) | | Eng 1 param. 7C.1.257.01

| | Eng 2 param. 7C.2.257.10 |--------------|--------------------------------------- | P25 | Total Air Pressure at Position 2.5 | 99999 | (0.0 to 30.000 psia) | | Eng 1 param. 7C.1.262.01 | | Eng 2 param. 7C.2.262.10 |--------------|--------------------------------------- | T25 | Selected T25 | X999 | (-30.0 to 300.0 C)

| | Eng 1 param. 7C.1.263.01 | | Eng 2 param. 7C.2.263.10 |--------------|---------------------------------------

| P3 | Selected PS3

+------------------------------------------------------ | Value | Content Description |--------------|--------------------------------------- | T3 | Temperature at Position 3 | X999 | (-89.0 to 700.0 C) | | Eng 1 param. 7C.1.265.01 | | Eng 2 param. 7C.2.265.10 |--------------|--------------------------------------- | P49 | Pressure on position 4.9 | 99999 | (1 to 25 psia) | | Eng 1 param. 7C.1.132.01 | | Eng 2 param. 7C.2.132.10

| |



|--------------|--------------------------------------- | SVA | Stator Vane Actuator Feedback | 999 | (0 to 100 %) | | Eng 1 param. 7C.1.325.01 | | Eng 2 param. 7C.2.325.10 |--------------|--------------------------------------- | BAF | 2.5 bleed Actuator Feedback | 999 | (0 to 100 %) | | Eng 1 param. 7C.1.335.01 | | Eng 2 param. 7C.2.335.10 |--------------|--------------------------------------- | ACC | Active Clearance Control Feedback | 999 | (0 to 100 %) | | Eng 1 param. 7C.1.330.01 | | Eng 2 param. 7C.2.330.10 |--------------|--------------------------------------- | LP | LPT ACC Solenoid Position | 01 | Bit status 1 = closed | | Eng 1 param. 7C.1.271.01.17 | | Eng 2 param. 7C.2.271.10.17 |--------------|--------------------------------------- | GLE | Engine Generator Load | 999 | (0 to 100 %) | | Eng 1 param. 29.1.077.01 | | 29.2.077.01 | | Eng 2 param. 29.1.077.10 | | 29.2.077.10

|--------------|--------------------------------------- | PD | Precooler Inlet Pressure | 99 | (0 to 50 psi)

| | Eng 1 param 06F 1 143 01

+------------------------------------------------------ | Value | Content Description |--------------|--------------------------------------- | TN | Nacelle Temperature | X99 | (-55 to 300 C) | | Eng 1 param. 26.1.322.01 | | 26.2.322.01 | | Eng 2 param. 26.1.322.10 | | 26.2.322.10 |--------------|--------------------------------------- | P2 | Total Air Pressure at Position 2 | 99999 | (0.0 to 25.000 psia)

| | E 1 7C 1 131 01



| | Eng 1 param. 7C.1.131.01 | | Eng 2 param. 7C.2.131.10 |--------------|--------------------------------------- | T2 | T2 Temperature | X999 | (-80 to 90.0 C) | | Eng 1 param. 7C.1.130.01 | | Eng 2 param. 7C.2.130.10 |--------------|--------------------------------------- | ECW1 | Engine Control Word 1 | XXXXX | Each X represents 4 Bits in hexade | | a defined ARINC 429 word: | | XXXXX Bits | | |||||___________ 14, 13, 12, 11 | | ||||____________ 18, 17, 16, 15 | | |||_____________ 22, 21, 20, 19 | | ||______________ 26, 25, 24, 23 | | |_______________ 29, 28, 27 | | ------------------------------------ | | Bit Label Parameter D | | 11 7C.X.270.XX.17 = 1 Manual Thru | | 12 7C.X.270.XX.18 = 1 N1 Rated Mod | | 13 7C.X.270.XX.20 = 1 Auto Thrust | | 14 7C.X.270.XX.21 = 1 2.5 Bleed F | | 15 7C.X.270.XX.23 = 1 Autothrust | | 16 SPARE | | 17 SPARE | | 18 7C.X.270.XX.27 = 1 SVA Failed

| | 19 7C.X.271.XX.16 = 1 FDV Off | | 20 SPARE | | 21 7C.X.271.XX.19 = 1 7th Bleed #

| | Closed (402

+------------------------------------------------------ | Value | Content Description |--------------|--------------------------------------- | | 24 7C.X.271.XX.28 = 1 P2/T2 Probe | | On | | 25 7C.X.351.XX.14 = 1 Left ADC Li | | 26 7C.X.351.XX.15 = 1 Right ADC L | | 27 SPARE | | 28 SPARE | | 29 SPARE |--------------|--------------------------------------- | ECW2 | Engine Control Word 2

| XXXXX | Each X represents 4 Bits in hexade



| XXXXX | Each X represents 4 Bits in hexade | | a defined ARINC 429 word: | | XXXXX Bits | | |||||___________ 14, 13, 12, 11 | | ||||____________ 18, 17, 16, 15 | | |||_____________ 22, 21, 20, 19 | | ||______________ 26, 25, 24, 23 | | |_______________ 29, 28, 27 | | ------------------------------------ | | Bit Label Parameter D | | 11 7C.X.272.XX.22 = 1 Bleed Config | | 12 7C.X.272.XX.23 = 1 Bleed Config | | 13 7C.X.272.XX.24 = 1 Bleed Config | | 14 7C.X.272.XX.25 = 1 Bleed Config | | 15 7C.X.272.XX.26 = 1 Bleed Config | | 16 7C.X.272.XX.27 = 1 Bleed Config | | 17 7C.X.272.XX.28 = 1 Bleed Config | | 18 SPARE | | 19 7C.X.272.XX.19 = 1 Bump Mode i | | 20 7C.X.272.XX.20 = 1 Bump Mode i | | 21 7C.X.272.XX.21 = 1 Bump Mode i | | 22 SPARE | | 23 SPARE | | 24 SPARE | | 25 SPARE | | 26 SPARE | | 27 SPARE | | 28 SPARE | | 29 SPARE |--------------|---------------------------------------

| EVM | Engine Vibration Status Word

+------------------------------------------------------ | Value | Content Description |--------------|--------------------------------------- | | XXXXX Bits | | |||||___________ 14, 13, 12, 11 | | ||||____________ 18, 17, 16, 15 | | |||_____________ 22, 21, 20, 19 | | ||______________ 26, 25, 24, 23 | | |_______________ 29, 28, 27 | | ------------------------------------ |--------------|--------------------------------------- | OIP | Engine Oil Pressure

| 999 | (0 to 400 psia)



| 999 | (0 to 400 psia) | | Eng 1 param. 26.1.317.01 | | 26.2.317.01 | | Eng 2 param. 26.1.317.10 | | 26.2.317.10 |--------------|--------------------------------------- | OIT | Engine Oil Temperature | X99 | (-60 to 250 C) | | Eng 1 param. 26.1.316.01 | | 26.2.316.01 | | Eng 2 param. 26.1.316.10 | | 26.2.316.10 |--------------|--------------------------------------- | OIQH | Oil Consumption from the previous fl | X999 | (-9.99 to 20.00 qts/h) |--------------|--------------------------------------- | VB1 | N1 Vibration | 999 | (0 to 10.0) | | Eng 1 param. 3D.1.135.01 | | Eng 2 param. 3D.1.135.10 |--------------|--------------------------------------- | VB2 | N2 Vibration | 999 | (0 to 10.0) | | Eng 1 param. 3D.1.136.01 | | Eng 2 param. 3D.1.136.10 |--------------|--------------------------------------- | PHA | FAN Pick Up Phase Angle | 999 | (0 to 360 deg) | | Eng 1 param. 3D.1.226.01 | | Eng 2 param. 3D.1.226.10

|--------------|---------------------------------------

+------------------------------------------------------ | Value | Content Description |--------------|--------------------------------------- |--------------|--------------------------------------- | ELEV | Elevator Position | X999 | (-30 to 15 deg) | | param. 6C.1.314.01 Left Elevator Pos | | param. 6C.2.314.10 | | param. 6C.1.334.01 Right Elevator Po | | param. 6C.2.334.10 |--------------|--------------------------------------- | AOA | Corrected Angle of Attack

| X999 | (-30 to 85 deg)



| X999 | ( 30 to 85 deg) | | param. 06.1.241.01 AOA System 1 | | param. 06.2.241.10 AOA System 2 |--------------|--------------------------------------- | SLP | Side Slip Angle | X999 | (-32.0 to 32.0 deg) | | param. 0A.1.226.00 System 1 | | param. 0A.2.226.00 System 2 |--------------|--------------------------------------- | CFPG | Side Slip Angle | X9999 | (-0.9999 to 4.0000 g) |--------------|--------------------------------------- | CIVV | Calculated Inertial Vertical Speed | X999 | (-999 to 999 ft/min) |--------------|--------------------------------------- | RUDD | Rudder Position | X999 | (-30.0 to 30.0 deg) | | param. 29.1.312.00 | | param. 29.2.312.00 |--------------|--------------------------------------- | RUDD | Rudder Trim Position | X999 | (-25.0 to 25.0 deg) | | param. 0A.1.313.00 | | param. 0A.2.313.00 |--------------|--------------------------------------- | AILL | Left Aileron Position | X999 | (-25.0 to 25.0 deg) | | param. 6C.1.310.01 | | param. 6C.2.310.10 |--------------|---------------------------------------

| AILR | Right Aileron Position

+------------------------------------------------------ | Value | Content Description |--------------|--------------------------------------- | STAB | Stabilizer Position #1

| X999 | (-13.5 to 4.0 deg) | | param. 6C.1.315.01 | | param. 6C.2.315.10 |--------------|--------------------------------------- | ROLL | Roll Angle | X999 | (-90.0 to 90.0 deg) | | param. 04.1.325.01 | | param. 04.2.325.10

|--------------|---------------------------------------



| | | YAW | Body Axis Yaw Rate | X999 | (-45.0 to 45.0 deg/sec) | | param. 04.1.330.01 | | param. 04.2.330.10 |--------------|--------------------------------------- | RSP2 | Roll Spoiler 2 Position | X999 | (-45.0 to 0 deg ) | | param. 6C.1.362.01 Left Spoiler | | param. 6C.2.362.10 | | param. 6C.1.372.01 Right Spoiler | | param. 6C.2.372.10 |--------------|--------------------------------------- | RSP3 | Roll Spoiler 3 Position | X999 | (-45.0 to 0 deg ) | | param. 6C.1.363.01 Left Spoiler | | param. 6C.2.363.10 | | param. 6C.1.373.01 Right Spoiler | | param. 6C.2.373.10 |--------------|--------------------------------------- | RSP4 | Roll Spoiler 4 Position | X999 | (-45.0 to 0 deg ) | | param. 6C.1.364.01 Left Spoiler | | param. 6C.2.364.10 | | param. 6C.1.374.01 Right Spoiler | | param. 6C.2.374.10 |--------------|--------------------------------------- | RSP5 | Roll Spoiler 5 Position | X999 | (-45.0 to 0 deg ) | | param. 6C.1.365.01 Left Spoiler

| | param 6C 2 365 10

+------------------------------------------------------ | Value | Content Description |--------------|--------------------------------------- | X999 | (-9.0 to 40.0 deg)

| | param. 1B.1.137.01 System 1 | | param. 1B.2.137.10 System 2 |--------------|--------------------------------------- | SLAT | Slat Actual Position | X999 | (-9.0 to 27.0 deg) | | param. 1B.1.127.01 System 1 | | param. 1B.2.127.10 System 2 |--------------|--------------------------------------- | THDG | True Heading (BCD)



g | X9999 | (0 to 359.9 deg) | | param. 04.1.044.01 System 1 | | param. 04.2.044.10 System 2 |--------------|--------------------------------------- | LONP | Longitude Position | X9999 | (East 179.9 deg to West 179.9 deg) | | param. 04.1.311.XX System 1 | | param. 04.2.311.XX System 2 |--------------|--------------------------------------- | LATP | Latitude Position | X9999 | (North 89.9 to South 89.9 deg) | | param. 04.1.310.XX System 1 | | param. 04.2.310.XX System 2 |--------------|--------------------------------------- | WS | Wind Speed | 999 | (0 to 100 kts) | | param. 04.1.315.01 System 1 | | param. 04.2.315.10 System 2 |--------------|--------------------------------------- | WD | WIND Direction - True | 999 | (0 to 359 deg) | | param. 04.1.316.01 System 1 | | param. 04.2.316.10 System 2 |--------------|--------------------------------------- | FT | Fuel Temperature | X999 | (-60.0 to 170.0 C) | | param. 5A.2.177.10 Fuel Temp. Left W | | param. 5A.2.201.10 Fuel Temp. Right |--------------|---------------------------------------

| FD | Fuel Temperature

(2) Cruise Performance Report Logic (Engine Type IAE)

+--------------------------------------------------------- |Code|Item | |Prog

| No.|No. | Description of Function Item |MCD | | | |GSE |----|------|-----------------------------------------|--- | |A | Report Format | | |B | Parameter Table | | |C | First three lines of Report | C | |D | Print Out Rules | C | |E | Transfer to ACARS MU | C | |F | Increment of the report counter if the | C



| | | report was triggered by a code number | | | | > 1000; 1=yes, 0=no | | |G | Averange intervales in seconds | AI | |H | Overall Average of F02 averages | AI | |I | OIQ values taken from taxi out used | | | | for QIQH calculation the same program- | | | | ming as for Report <01> is apply. | |----|------|-----------------------------------------|--- |1000|1 | Manual selection via MCDU | |----|------|-----------------------------------------|--- |2000|2 | Flight phase dependent manual | | | | selection via remote print button | | | | if programmed. | | |2.1 | Logic algorithm | | |2.2 | Remote Print Button assignment | C |----|------|-----------------------------------------|--- |3000|3 | Programmable Start Logic | | |3.1 | Logic algorithm | C | |3.2 | Trigger condition | C |----|------|-----------------------------------------|--- |5000| | The DMU generates the Cruise Performance| | | | Report based on Flight Hours or | | | | Flight Legs programmable via GSE. | | | | | | | | Logic based on Flight Hours: | | | | | | | | During a time frame of Y02.1 flight | | | | hours the DMU search in flight phase 6 | | | | for report generation with stable frame |

| | | criteria where the best aircraft quality|

+--------------------------------------------------------- |Code|Item | |Prog | No.|No. | Description of Function Item |MCD | | | |GSE

|----|------|-----------------------------------------|--- | | | Logic based on Flight Legs: | | | | | | | | Every Y02.2 flight legs the DMU search| | | | in flight phase 6 for report generation | | | | with stable frame criteria where the | | | | best aircraft quality number QA is cal- | | | | culated. The report with the best quali-| | | | ty number QA is stored in the report |



| | | buffer. | | | | | | |5 | The default programming is Flight Legs| C | | | | | |5.1 | Logic algorithm | | | | | | |5.2 | Y02.1 flight hours | C | | | | | |5.3 | Y02.2 flight legs | C | | | | | |5.4 | PO2 stable periods | C | | | (5 subperiods = 100 sec) | | |5.5 | 78% < ACC < 100% | | | | param. 7C.1.330.01 Eng.1 | | | | param. 7C.2.330.10 Eng.2 | | | | | | | | Stable frame conditions: | | | | During P02 seconds the following | | | | parameters are stable as defined below: | | | | | | | | The stable frame variation is customer | | | | programmable, but only in the range | | | | defined in the column for standard | | | | values. | | | | | | |5.6 | IALT 04.1.361.-- ft | AI | | | 04.2.361.-- | | | | | | |5.6.1 | WA of IALT | C

| | | |

+--------------------------------------------------------- |Code|Item | |Prog | No.|No. | Description of Function Item |MCD | | | |GSE

|----|------|-----------------------------------------|--- | | | | | |5.8 | ROLL ANGLE 04.1.325.01 degr. | AI | | | 04.2.325.10 | | |5.8.1 | WA of ROLL ANGLE | C | | | | | |5.9 | TAT 06.1.211.01 C | AI | | | 06.2.211.10 | | |5.9.1 | WA of TAT | C



| | | | | |5.10 | N2 7C.1.344.01 Eng.1 % | AI | | | 7C.2.344.10 Eng.2 | | |5.10.1| WA of N2 | C | | | | | |5.11 | EGT 7C.1.345.01 Eng.1 C | AI | | | 7C.2.345.10 Eng 2 | | |5.11.1| WA of EGT | C | | | |

| |5.12 | VACC 04.1.364.01 g | AI | | | 04.2.364.10 | | |5.12.1| WA of VACC | C | | | | | |5.13 | MN 06.1.205.01 Mach | AI | | | 06.2.205.10 | | |5.13.1| WA of MN | C | | | | | |5.14 | N1 7C.1.346.01 Eng.1 % | AI | | | 7C.2.346.10 Eng.2 | | |5.14.1| WA of N1 | C | | | | | |5.15 | PT2 7C.1.131.91 Eng.1 psia | AI | | | 7C.2.131.10 Eng.2 | | |5.15.1| WA of PT2 | C | | | | | |5.16 | FF 7C.1.244.01 Eng.1 kg/h | AI | | | 7C.2.244.10 Eng.2 | | |5.16.1| WA of FF | C | | | |

| |5 17 | EPR 7C 1 340 01 Eng 1 % | AI



6. APPENDIX 6 - AUDITING AIRCRAFT CRUISE PER

AIRLINE REVENUE SERVICE

The following pages are a copy of the article that was distribuPerformance and Operations Conference held at Cancun, MeThis brochure is based upon the leading article “Auditinperformance in airline revenue service” presented by Mr. J.J. SPused as reference material.



I. GLOSSARY

Greek lettersαααα ( alpha ) Angle of attack

γ γγ γ ( gamma ) Climb or descent angle

δδδδ ( delta ) Pressure ratio = P / P0

∆∆∆∆ ( DELTA ) Parameters’ variation (ex : ∆∆∆∆ISA,

φφφφ ( phi ) Bank angle

θθθθ ( theta ) Aircraft attitude

ρρρρ ( rho ) Air density

ρρρρ0 ( rho zero ) Air density at Mean Sea Level

σσσσ ( sigma ) Air density ratio = ρρρρ / ρρρρ0

AACARS Aircraft Communication Addressing and Rep



ACARS Aircraft Communication Addressing and Rep

ADIRS Air Data / Inertial Reference System

ADIRU Air Data/Inertial Reference Unit

AFM Aircraft Flight Manual

AIDS Aircraft Integrated Display System

ALD Actual Landing DistanceAMC Acceptable Means of Compliance (JAA)AMJ Advisory Material Joint (JAA)AOM Airline Operation Manual

APM Aircraft Performance Monitoring (program)

APU Auxiliary Power Unit

ARMS Aircraft Recording and Monitoring System

ATC Air Traffic Control

ATSU Air Traffic Service Unit

B



HhPa hecto Pascal

IIAS Indicated Air SpeedICAO International Civil Aviation OrganizationIFP In Flight Performance (program)IFR Instrument Flight RulesIL Information Leaflet (JAA)IMC Instrument Meteorological Conditionsin Hg Inches of mercury

ISA International Standard Atmosphere

JJAA Joint Aviation AuthorityJAR Joint Airworthiness Requirements



KKi Instrumental correction (Antenna error)

LLAT LatitudeLPC Less Paper Cockpit (program)LRC Long Range Cruise speed

MMLR Mach of Long RangeMMR Mach of Maximum RangeMMO Maximum Operating Mach number

MCDU Multipurpose Control and Display Unit

MDDU Multipurpose Disk Drive Unit

MCT Maximum Continuous Thrust

G LOSSARY

Nn Load factor nz Load factor component normal to the aircraft’s lo

axis

N1 Speed rotation of the fanNLC Noise Level Computation (program)NPA Notice for Proposed Amendment (JAA)NPRM Notice for Proposed Rule Making (FAA)

OOAT Outside Air Temperature

OCTOPUS Operational and Certified Takeoff and landing Software

OEW Operational Empty WeightOFP Operational Flight Path (program)

P



P Pressure

P0 Standard pressure at Mean Sea LevelPEP Performance Engineering ProgramsPFD Primary Flight Display

QQAR Quick Access Recorder

Optional equipment

SSAR Smart Access Recorder

Internal DMU/FDIMU memory

SAT Static Air Temperature

SFC Specific Fuel ConsumptionSR Specific Range

TT TemperatureT0 Standard temperature at Mean Seal LevelTISA Standard temperature

TREF Flat Rating TemperatureTAS True Air SpeedTAT Total Air TemperatureTLC Takeoff and Landing Computation (program)TLO TakeOff and Landing Optimization (program)TOGA TakeOff / Go-Around thrustTOW TakeOff Weight

VV VelocityVLS Lowest selectable speedVMO Maximum Operating speedVS Stalling speedV Stalling speed at one g



VS1G Stalling speed at one gV

SRReference stalling speed

VFR Visual Flight RulesVMC Visual Meteorological Conditions

WW WeightWa Apparent weightWC Wind component

ZZFW Zero Fuel Weight

G LOSSARY




J. BIBLIOGRAPHY

[J-1] 7th Performance and Operations Conference – “Audit

performance in airline revenue service”, Jean JacquesFlight Operations & Line Assistance, STL. Leading articlebrochure (Appendix 6).

[J-2] Performance Programs Manual

[J-3] “Getting hands-on-experience with aerodynamic detbrochure, reference STL 945.3399/96, October 2001, Issu



For any comment, suggestion, or enquiry concerning this brocthe Airbus Customer Services, Flight Operations Support department (STL)Fax: +33 561 93 29 68/44 65,E-mail : [email protected]

AIRBUS



AIRBUS

31707 Blagnac CedexFrance

Ref.: STL 94B.0510/02

© Airbus 2002

All rights reserved.

A R O U

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C L

O C K

A I R

B U S C U S T OM E R S E

R V I C E S

c e

g e t t i n g

t o

g r i p s

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a i r c r a f t p e r f o r m

a n c e

m

o n i t o r i n g

D e c e m b e r 2 0 0 2



AIRBUS S.A.S.

31707 BLAGNAC CEDEX - FRANCE

CONCEPT DESIGN SCM12

REFERENCE SCM1-D388

DECEMBER 2002

PRINTED IN FRANCE

© AIRBUS S.A.S. 2002

ALL RIGHTS RESERVED

AN EADS JOINT COMPANY

WITH BAE SYSTEMS

AIRBUS

The statements made herein do not constitute an offer. They are based on the assumptions show n and are expressed in good faith. Where the

supporting grounds for these statements are not shown, the Company will be pleased to explain the basis thereof. This document is the property of Airbus and is suppl ied on the express

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